Treatment liquid for manufacturing semiconductor, storage container storing treatment liquid for manufacturing semiconductor, pattern forming method, and method of manufacturing electronic device

ABSTRACT

A storage container storing a treatment liquid for manufacturing a semiconductor is provided, wherein the occurrence of defects on the semiconductor, such as particles, is suppressed and a fine resist pattern or a fine semiconductor element is manufactured. The storage container includes a storage portion that stores a treatment liquid for manufacturing a semiconductor, and the treatment liquid for manufacturing a semiconductor includes one kind or two or more kinds of metal atoms and a total content of particulate metal is 0.01 to 100 mass ppt with respect to a total mass of the treatment liquid.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No.PCT/JP2017/010618, filed Mar. 16, 2017, and based upon and claiming thebenefit of priority from Japanese Patent Applications No. 2016-073257,filed Mar. 31, 2016; and No. 2017-045864, filed Mar. 10, 2017, theentire contents of all of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a treatment liquid for manufacturing asemiconductor, such as a developer, a rinsing liquid, a pre-wet liquid,an etchant, a cleaning liquid, or a peeling liquid, that is used inmanufacturing steps of a semiconductor device, a storage containerstoring the treatment liquid for manufacturing a semiconductor, apattern forming method, and a method of manufacturing an electronicdevice.

2. Description of the Related Art

The manufacturing steps of a semiconductor device include various stepssuch as a lithography step, an etching step, an ion implantation step,or a peeling step. In general, a step of treating unnecessary organicmatters and inorganic matters using a treatment liquid is provided afterthe end of each step or before the start of the next step. For example,a development step of treating an exposed resist film using a developer,a peeling step of treating a resist remaining on a surface of a treatedsubstrate using a peeling liquid, or a rinsing step of further purifyingthe surface using a rinsing liquid after the development step or thepeeling step may be provided.

A small amount of impurities included in various treatment liquids, suchas a developer, a rinsing liquid, a pre-wet liquid, an etchant, acleaning liquid, or a peeling liquid used in the manufacturing steps ofa semiconductor device (hereinafter, referred to as “treatment liquidsfor manufacturing a semiconductor”) cause various defects, and thus theyield of products or the reliability deteriorates. Therefore, thetreatment liquid for manufacturing a semiconductor is required to havehigh purity.

In particular, products have required higher accuracy along withsignificant recent development of the electronic material industry, anda small amount of impurities included in the treatment liquid formanufacturing a semiconductor, in particular, in a developer, a rinsingliquid, or the like used in a photolithography step and contaminationfrom a container storing the treatment liquid for manufacturing asemiconductor have become problematic. Therefore, requirements for highpurity have become more strict.

Therefore, an organic treatment liquid for patterning a resist film withwhich the formation of particles can be reduced or a storage containerin which the incorporation or elution of fine particles of components ofthe container into a stored solution is suppressed has been developed.For example, JP2014-112176A, JP2008-179774A, and JP2015-123351A can bereferred to.

SUMMARY OF THE INVENTION

Metal impurities included in the treatment liquid for manufacturing asemiconductor cause defects such as particles. Therefore, it isconsidered that, the less the amount of metal impurities, the better.The present inventors clarified that the amount of metal impurities andthe occurrence of defects do not necessarily relate to each other andthe occurrence of defects cannot be necessarily suppressed simply byreducing the amount of metal impurities in the treatment liquid.

The present invention has been developed under the above-describedcircumstances, and an object thereof is to provide a treatment liquidfor manufacturing a semiconductor with which the occurrence of defectssuch as particles is suppressed such that a fine resist pattern or afine semiconductor element can be manufactured, and a storage containerstoring the treatment liquid for manufacturing a semiconductor. Anotherobject of the present invention is to provide a pattern forming methodusing the treatment liquid for manufacturing a semiconductor and amethod of manufacturing an electronic device.

The present invention is as follows.

[1] A storage container comprising:

a storage portion that stores a treatment liquid for manufacturing asemiconductor,

in which the treatment liquid for manufacturing a semiconductor includesone kind or two or more kinds of metal atoms selected from Cu, Fe, andZn, and

a total content of particulate metal including at least one kind of themetal atoms is 0.01 to 100 mass ppt with respect to a total mass of thetreatment liquid for manufacturing a semiconductor.

[2] The storage container according to [1],

in which a mass of the particulate metal is measured by a SP-ICP-MSmethod.

[3] The storage container according to [1] or [2],

in which an inner wall of the storage portion that comes into contactwith the treatment liquid for manufacturing a semiconductor is cleanedusing a cleaning liquid having a contact angle of 10 degrees to 120degrees on the inner wall before being filled with the treatment liquidfor manufacturing a semiconductor.

[4] The storage container according to [3],

in which the cleaning liquid is ultrapure water or a liquid including atleast one of components included in the treatment liquid formanufacturing a semiconductor.

[5] The storage container according to any one of [1] to [4],

in which at least a portion of an inner wall of the storage portion thatcomes into contact with the treatment liquid for manufacturing asemiconductor is formed of a material including at least one selectedfrom the group consisting of polyethylene, polypropylene,polytetrafluoroethylene, and perfluoroalkoxy alkane.

[6] The storage container according to any one of [1] to [5],

in which at least a portion of an inner wall of the storage portion thatcomes into contact with the treatment liquid for manufacturing asemiconductor is formed of a material including at least one selectedfrom the group consisting of stainless steel, HASTELLOY (registeredtrade name), INCONEL (registered trade name), and MONEL.

[7] The storage container according to any one of [1] to [5],

in which at least a portion of an inner wall of the storage portion thatcomes into contact with the treatment liquid for manufacturing asemiconductor is formed of a material including at least one selectedfrom the group consisting of stainless steel, HASTELLOY, INCONEL, andMONEL, and

a mass ratio represented by Cr/Fe in a portion having a depth of 1 nmfrom an outermost surface of the inner wall is 1 to 3.

[8] The storage container according to any one of [1] to [7],

in which an occupancy ratio of a void portion in the storage portionstoring the treatment liquid for manufacturing a semiconductor is 50 to0.01 vol %.

[9] The storage container according to any one of [1] to [8],

in which a void portion of the storage portion storing the treatmentliquid for manufacturing a semiconductor is filled with gas in which thenumber of particles having a diameter of 0.5 μm or more is 10particles/L or less.

[10] The storage container according to any one of [1] to [9],

in which a void portion of the storage portion storing the treatmentliquid for manufacturing a semiconductor is filled with inert gas.

[11] The storage container according to any one of [1] to [10],

in which the treatment liquid for manufacturing a semiconductor is adeveloper or a rinsing liquid.

[12] The storage container according to any one of [1] to [11],

in which the treatment liquid for manufacturing a semiconductor includesa quaternary ammonium salt.

[13] The storage container according to any one of [1] to [11],

in which the treatment liquid for manufacturing a semiconductor includesat least one selected from the group consisting of butyl acetate,N-methyl-2-pyrrolidone, isopropanol, ethanol, and methyl isobutylcarbinol.

[14] A treatment liquid for manufacturing a semiconductor comprising:

one kind or two or more kinds of metal atoms selected from Cu, Fe, andZn,

in which a total content of particulate metal including at least onekind of the metal atoms is 0.01 to 100 mass ppt with respect to a totalmass of the treatment liquid for manufacturing a semiconductor.

[15] The treatment liquid for manufacturing a semiconductor according to[14], in which a mass of the particulate metal is measured by aSP-ICP-MS method.

[16] The treatment liquid for manufacturing a semiconductor according to[14] or [15], which is a developer or a rinsing liquid.

[17] The treatment liquid for manufacturing a semiconductor according toany one of [14] to [16], further comprising:

a quaternary ammonium salt.

[18] The treatment liquid for manufacturing a semiconductor according toany one of [14] to [17], further comprising:

at least one selected from the group consisting of butyl acetate,N-methyl-2-pyrrolidone, isopropanol, ethanol, and methyl isobutylcarbinol.

[19] A pattern forming method comprising:

a step of applying an actinic ray-sensitive or radiation-sensitive resincomposition to a substrate to form an actinic ray-sensitive orradiation-sensitive film;

a step of exposing the actinic ray-sensitive or radiation-sensitivefilm; and

a step of treating the substrate or the actinic ray-sensitive orradiation-sensitive film using the treatment liquid for manufacturing asemiconductor according to any one of [14] to [18].

[20] The pattern forming method according to [19],

in which the pattern forming method comprises at least a step ofdeveloping the actinic ray-sensitive or radiation-sensitive film byusing the treatment liquid for manufacturing a semiconductor as adeveloper as the step of treating the substrate or the actinicray-sensitive or radiation-sensitive film using the treatment liquid formanufacturing a semiconductor.

[21] The pattern forming method according to [19],

in which the pattern forming method comprises at least a step ofcleaning the actinic ray-sensitive or radiation-sensitive film by usingthe treatment liquid for manufacturing a semiconductor as a rinsingliquid as the step of treating the substrate or the actinicray-sensitive or radiation-sensitive film using the treatment liquid formanufacturing a semiconductor.

[22] A method of manufacturing an electronic device comprising:

the pattern forming method according to any one of [19] to [21].

According to the present invention, it is possible to provide atreatment liquid for manufacturing a semiconductor with which theoccurrence of defects such as particles is suppressed such that a fineresist pattern or a fine semiconductor element can be manufactured, anda storage container storing the treatment liquid for manufacturing asemiconductor. In addition, according to the present invention, it ispossible to provide a pattern forming method using the treatment liquidfor manufacturing a semiconductor and a method of manufacturing asemiconductor device including the pattern forming method.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a contact angle.

FIG. 2 is a schematic diagram showing an aspect of a manufacturingdevice that can be used in a method of manufacturing a treatment liquidaccording to an embodiment of the present invention.

FIG. 3 is a schematic diagram showing another aspect of themanufacturing device that can be used in the method of manufacturing thetreatment liquid according to the embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In this specification, unless specified as a substituted group or as anunsubstituted group, a group (atomic group) denotes not only a grouphaving no substituent but also a group having a substituent. Forexample, “alkyl group” denotes not only an alkyl group having nosubstituent (unsubstituted alkyl group) but also an alkyl group having asubstituent (substituted alkyl group).

In this specification, “actinic ray” or “radiation” denotes, forexample, a bright light spectrum of a mercury lamp, a far ultravioletray represented by excimer laser, an extreme ultraviolet lithography ray(EUV ray), an X-ray, or an electron beam (EB). In addition, in thepresent invention, “light” denotes an actinic ray or radiation.

In addition, in this specification, unless specified otherwise,“exposure” denotes not only exposure using a mercury lamp, a farultraviolet ray represented by excimer laser, an X-ray, an EUV ray, orthe like but also drawing using a corpuscular beam such as an electronbeam or an ion beam.

In addition, in this specification, “(meth)acrylate” represents “atleast one of acrylate or methacrylate”. In addition, “(meth)acrylicacid” represents “at least one of acrylic acid or methacrylic acid”.

In addition, in this specification, numerical ranges represented by “to”include numerical values before and after “to” as lower limit values andupper limit values.

Hereinafter, embodiments of the present invention will be described indetail.

<Treatment Liquid for Manufacturing Semiconductor>

As described above, in manufacturing steps of a semiconductor deviceincluding a lithography step, an etching step, and an ion implantationstep, “treatment liquid for manufacturing a semiconductor” according tothe present invention is a treatment liquid used for treating an organicmatter before the end of each step or after the start of the next step,and is, for example, a treatment liquid used as a developer, a rinsingliquid, a pre-wet liquid, an etchant, a cleaning liquid, or a peelingliquid.

The treatment liquid for manufacturing a semiconductor according to thepresent invention (hereinafter, also referred to as “the treatmentliquid according to the present invention) includes one kind or two ormore kinds of metal atoms selected from Cu, Fe, and Zn, and a totalcontent of particulate metal including at least one kind of the metalatoms is 0.01 to 100 mass ppt (parts per trillion) with respect to thetotal mass of the treatment liquid.

The metal elements selected from metal species (hereinafter, alsoreferred to as “target metals” or the like”) including Cu, Fe, and Znare included in the treatment liquid for manufacturing a semiconductoras impurities. Particles including these metal elements form defects andhave a large effect on the formation of a fine resist pattern or a finesemiconductor element. Therefore, it has been considered that, as theamount of metal atoms included in the treatment liquid for manufacturinga semiconductor decreases, the occurrence of defects during themanufacturing of a semiconductor is reduced, which is preferable.However, the present inventors found that the amount of metal atoms inthe treatment liquid and the rate of occurrence of defects do notnecessarily relate to each other and there is a variation in the rate ofoccurrence of defects.

However, according to the recently developed Single-Particle ICP-MS(SP-ICP-MS) measurement, as the amount of metal atoms present in asolution, the amount of ionic metal and the amount of particulate metal(nonionic metal) can be dividedly measured. Here, the particulate metal(nonionic metal) refers to a metal component present in a solution as asolid without being dissolved.

In the related art, the amount of metal atoms included in a treatmentliquid for manufacturing a semiconductor is typically analyzed using theICP-MS method. Depending on ICP-MS, the ionic metal and the particulatemetal (nonionic metal) including at least one kind of the metal atomscannot be distinguished from each other, and thus the quantity thereofis determined as the total mass of the metal atoms, that is, the totalmass (hereinafter, also referred to as “total metal amount”) of theionic metal and the particulate metal (nonionic metal).

Now that the ionic metal and the particulate metal can be distinguishedfrom each other and the quantities thereof can be determined using thesingle-particle ICP-MS (SP-ICP-MS) measurement, the present inventorsconducted a thorough research on the effect of each of the ionic metaland the particulate metal (nonionic metal) derived from the metal atomsin the treatment liquid on defects.

As a result, it was found that the amount of the particulate metal(nonionic metal) has an extremely large effect on the occurrence ofdefects and there is a correlation between the amount of the particulatemetal (nonionic metal) and the occurrence of defects.

The present invention has been completed based on the above findings,and has one characteristic that the content of the total mass ofparticulate metal including at least one kind of the metal atomsselected from the Cu, Fe, and Zn as the target metals is 0.01 to 100mass ppt with respect to the total mass of the treatment liquid.Hereinafter, for example, this content will also be referred to as “thecontent of the particulate metal”.

The content of the particulate metal in the treatment liquid accordingto the present invention is preferably 0.01 to 50 mass ppt and morepreferably 0.01 to 10 mass ppt with respect to the total mass of thetreatment liquid according to the present invention.

Examples of a device that can be used for the measurement using theSP-ICP-MS method include a device (NexION350S, manufactured byPerkinElmer Co., Ltd.) used in Examples described below, Agilent 8800triple quadrupole ICP-MS (inductively coupled plasma mass spectrometry;manufactured by Agilent Technologies Inc.; for analyzing asemiconductor, option #200), and Agilent 8900 (manufactured by AgilentTechnologies Inc.).

As described above, in a case where the treatment liquid according tothe present invention may be used as any one of a developer, a rinsingliquid, a pre-wet liquid, an etchant, a cleaning liquid, a peelingliquid, and the like used in the manufacturing steps of a semiconductordevice. In one aspect of the present invention, it is preferable thatthe treatment liquid is used as a developer or a rinsing liquid.

In a case where the treatment liquid according to the present inventionis used as a developer, the developer may be an alkali developer or adeveloper including an organic solvent.

In a case where the treatment liquid according to the present inventionis used as an alkali developer, it is preferable that the treatmentliquid according to the present invention is an aqueous solutionincluding a quaternary ammonium salt represented by tetramethylammoniumhydroxide (TMAH). In addition, the treatment liquid according to thepresent invention may be an alkali aqueous solution including aninorganic alkali, primary to tertiary amines, an alcohol amine, or acyclic amine.

Specific examples of the alkali developer include an alkaline aqueoussolution including: an inorganic alkali such as sodium hydroxide,potassium hydroxide, sodium carbonate, sodium silicate, sodiummetasilicate, or ammonia water; a primary amine such as ethylamine orn-propyl amine; a secondary amine such as diethylamine ordi-n-butylamine; a tertiary amine such as triethylamine ormethyldiethylamine; an alcohol amine such as dimethylethanolamine ortriethanolamine; a quaternary ammonium salt such as tetramethylammoniumhydroxide or tetraethylammonium hydroxide; or a cyclic amine such aspyrrole or piperidine. Among these, an aqueous solution includingtetramethylammonium hydroxide or tetraethylammonium hydroxide ispreferable.

Further, an appropriate amount of an alcohol or a surfactant may beadded to the alkali developer. The alkali concentration in the alkalideveloper is typically 0.1 to 20 mass %. The pH of the alkali developeris typically 10.0 to 15.0.

A period of time during which development is performed using the alkalideveloper is typically 10 to 300 seconds.

The alkali concentration (and pH) and development time of the alkalideveloper can be appropriately adjusted according to a pattern to beformed.

In a case where the treatment liquid according to the present inventionis used as a developer including an organic solvent (hereinafter, alsoreferred to as “organic developer”), as the organic solvent, a polarsolvent such as a ketone solvent, an ester solvent, an alcohol solvent,an amide solvent, or an ether solvent or a hydrocarbon solvent can beused. As the solvent used in the present invention, a solvent in whichthe concentration of an inorganic ion such as a sulfate ion, a chlorideion, or a nitrate ion and the concentration of Fe, Cu, and Zn as thetarget metals are reduced can be used, and it is more preferable thatthe solvent is further reduced for use.

Examples of the ketone solvent include 1-octanone, 2-octanone,1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone),4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone,methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol,acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, andpropylene carbonate.

Examples of the ester solvent include methyl acetate, butyl acetate,ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate,amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycolmonoethyl ether acetate, diethylene glycol monobutyl ether acetate,diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate,3-methoxy butyl acetate, 3-methyl-3-methoxy butyl acetate, methylformate, ethyl formate, butyl formate, propyl formate, ethyl lactate,butyl lactate, and propyl lactate.

Examples of the alcohol solvent include: an alcohol such as methylalcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol (IPA),n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutylalcohol, 4-methyl-2-pentanol (methyl isobutyl carbinol; MIBC), n-hexylalcohol, n-heptyl alcohol, n-octyl alcohol, or n-decanol; a glycolsolvent such as ethylene glycol, diethylene glycol, or triethyleneglycol; and a glycol ether solvent such as ethylene glycol monomethylether, propylene glycol monomethyl ether, ethylene glycol monoethylether, propylene glycol monoethyl ether, diethylene glycol monomethylether, triethylene glycol monoethyl ether, or methoxy methyl butanol.

Examples of the ether solvent include the above-described glycol ethersolvents, dioxane, and tetrahydrofuran.

Examples of the amide solvent include N-methyl-2-pyrrolidone (NMP),N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphoricamide, and 1,3-dimethyl-2-imidazolidinone.

Examples of the hydrocarbon solvent include: an aromatic hydrocarbonsolvent such as toluene or xylene; and an aliphatic hydrocarbon solventsuch as pentane, hexane, octane, decane, or undecane.

A mixture of a plurality of kinds among the organic solvents may beused, or a mixture of one of the organic solvents and a solvent otherthan the organic solvents or water may be used. However, in order tosufficiently exhibit the effects of the present invention, it ispreferable that the moisture content is lower than 10 mass % withrespect to the total mass of the developer, and it is more preferablethat the developer does not substantially include water.

In particular, it is preferable that the organic developer is adeveloper including at least one organic solvent selected from the groupconsisting of a ketone solvent, an ester solvent, an alcohol solvent, anamide solvent, and an ether solvent.

A vapor pressure of the organic developer at 20° C. is preferably 5 kPaor lower, more preferably 3 kPa or lower, and still more preferably 2kPa or lower. By adjusting the vapor pressure of the organic developerto be 5 kPa or lower, evaporation of developer on a substrate or in adeveloping cup suppressed, and uniformity in the temperature in a wafersurface is improved. As a result, uniformity in the dimension in a wafersurface is improved.

Optionally, an appropriate amount of a surfactant can be added to theorganic developer.

The surfactant is not particularly limited. For example, an ionic ornonionic fluorine surfactant and/or an ionic or nonionic siliconsurfactant can be used. Examples of the fluorine and/or siliconsurfactant include surfactants described in JP1987-36663A(JP-S62-36663A), JP1986-226746A (JP-S61-226746A), JP1986-226745A(JP-S61-226745A), JP1987-170950A (JP-S62-170950A), JP1988-34540A(JP-S63-34540A), JP1995-230165A (JP-H7-230165A), JP1996-62834A(JP-H8-62834A), JP1997-54432A (JP-H9-54432A), JP1997-5988A(JP-H9-5988A), U.S. Pat. Nos. 5,405,720A, 5,360,692A, 5,529,881A,5,296,330A, 5,436,098A, 5,576,143A, 5,294,511A, and 5,824,451A. Amongthese, a nonionic surfactant is preferable. The nonionic surfactant isnot particularly limited, and a fluorine surfactant or a siliconsurfactant is more preferable.

The amount of the surfactant used is typically 0.001 to 5 mass %,preferably 0.005 to 2 mass %, and more preferably 0.01 to 0.5 mass %with respect to the total mass of the developer.

It is preferable that the organic developer is butyl acetate.

In addition, the organic developer may include a nitrogen-containingcompound described in paragraphs “0041” to “0063” of JP5056974B. Fromthe viewpoint of storage stability of the developer or the like, it ispreferable that the addition of the nitrogen-containing compound to theorganic developer is performed immediately before the formation of apattern.

In a case where the treatment liquid according to the present inventionis a rinsing liquid, it is preferable that the treatment liquidaccording to the present invention includes an organic solvent. As thesolvent used in the present invention, a solvent in which theconcentration of an inorganic ion such as a sulfate ion, a chloride ion,or a nitrate ion and the concentration of Fe, Cu, and Zn as the targetmetals are reduced can be used, and it is more preferable that thesolvent is further reduced for use.

The amount of the organic solvent used in the rinsing liquid includingan organic solvent (hereinafter, referred to as “organic rinsingliquid”) is preferably 90 mass % to 100 mass %, and more preferably 95mass % to 100 mass % with respect to the total amount of the rinsingliquid.

The organic rinsing liquid is not particularly limited as long as itdoes not dissolve a resist pattern, and a solution including a generalorganic solvent can be used. In a case where the treatment liquidaccording to the present invention is used as the organic rinsingliquid, it is preferable that the treatment liquid according to thepresent invention includes at least one organic solvent selected fromthe group consisting of a hydrocarbon solvent, a ketone solvent, anester solvent, an alcohol solvent, an amide solvent, and an ethersolvent.

Specific examples of the hydrocarbon solvent, the ketone solvent, theester solvent, the alcohol solvent, the amide solvent, and the ethersolvent include the examples described above regarding the organicdeveloper.

Among these, it is preferable that the treatment liquid according to thepresent invention as the organic rinsing liquid includes at least oneselected from the group consisting of N-methyl-2-pyrrolidone (NMP),isopropanol (IPA), ethanol, and 4-methyl-2-pentanol (MIBC).

The moisture content in the organic rinsing liquid is preferably 10 mass% or lower, more preferably 5 mass % or lower, and still more preferably3 mass % or lower. By adjusting the moisture content to be 10 mass % orlower, excellent developing characteristics can be obtained.

A vapor pressure of the organic rinsing liquid at 20° C. is preferably0.05 kPa or higher and 5 kPa or lower, more preferably 0.1 kPa or higherand 5 kPa or lower, and most preferably 0.12 kPa or higher and 3 kPa orlower. By adjusting the vapor pressure of the rinsing liquid to be 0.05kPa or higher and 5 kPa or lower, uniformity in the temperature in awafer surface is improved. Further, swelling of the resist film causedby permeation of the rinsing liquid is suppressed, and uniformity in thedimension in a wafer surface is improved.

An appropriate amount of the surfactant can also be added to the organicrinsing liquid.

[Method of Adjusting Metal Content]

In the treatment liquid according to the present invention, the ionconcentration of each of Na, Ca, Al, Cr, Co, Pb, Li, Mg, Mn, Ni, K, Ag,and the like is preferably 1 ppm (parts per million) or lower and morepreferably 1 ppb or lower. In particular, it is more preferable that theion concentration is in the order of ppt (all the concentrations arebased on mass), and it is still more preferable that the treatmentliquid does not substantially include Na, Ca, Al, Cr, Co, Pb, Li, Mg,Mn, Ni, K, Ag, and the like.

The metal content of the treatment liquid according to the presentinvention may be adjusted by repeating distillation, filter filtration,filtration using an ion exchange resin, adsorption purification, or thelike to sufficiently purify the treatment liquid, for example, at leastone of a step of preparing the respective raw materials used formanufacturing the treatment liquid or a step after the preparation ofthe treatment liquid.

Here, the method of adjusting the metal content (hereinafter, alsoreferred to as “method of reducing the metal concentration”) is notparticularly limited, and examples thereof include adsorptionpurification using silicon carbide described in WO2012/043496A. Further,an example of using the adsorption purification in combination withdistillation, filter filtration, or filtration using an ion exchangeresin to sufficiently purify the treatment liquid is also preferable.

From the viewpoint of obtaining the effects of the present invention, itis more preferable that the method of adjusting the metal content isperformed in the step of preparing the respective raw materials used formanufacturing the treatment liquid. In addition, in the raw materials,it is preferable that the content of the specific metal atoms or thecontent of an inorganic ion such as a sulfate ion, a chloride ion, or anitrate ion and a specific metal ion are reduced.

In another method relating to the method of reducing the metalconcentration, for example, as “container” that stores the raw materialsused for manufacturing the treatment liquid, a container in which theelution of impurities is reduced as described below regarding a storagecontainer that stores the treatment liquid according to the presentinvention. In addition, for example, a method of lining an inner wall ofthe pipe with a fluororesin to prevent the specific metal atoms frombeing eluted from “the pipe” or the like used for the preparation of thetreatment liquid can also be used.

[Impurities and Coarse Particles]

In addition, it is preferable that the treatment liquid according to thepresent invention does not substantially include coarse particles.

Here, the coarse particles included in the treatment liquid refer toparticles of dirt, dust, an organic solid matter, an inorganic solidmatter, or the like included in raw materials as impurities or particlesof dirt, dust, an organic solid matter, an inorganic solid matter, orthe like introduced as a contaminant during the preparation of thetreatment liquid. The coarse particles correspond to particles thatfinally remain in the treatment liquid without being dissolved. Theamount of the coarse particles present in the treatment liquid can bemeasured in a liquid phase using a commercially available measuringdevice according to a light scattering particle measurement method inliquid in which a laser is used as a light source.

It is preferable that the treatment liquid according to the presentinvention is stored in a storage container described below.

<Storage Container Storing Treatment Liquid for ManufacturingSemiconductor>

The present invention relates to a storage container (hereinafter, alsoreferred to as “storage container according to the present invention”)including a storage portion that stores the treatment liquid accordingto the present invention.

It is preferable that the storage container according to the presentinvention is a container with which an increase in the content of theparticulate metal in the treatment liquid according to the presentinvention stored in the storage container can be suppressed and thecontent of the particulate metal in the treatment liquid even after along-term storage can be maintained in a range of 0.01 to 100 mass %.

In one aspect, the storage container according to the present inventionincludes: a storage portion that stores the treatment liquid accordingto the present invention; and a seal portion that seals the storageportion.

In one aspect of the present invention, it is preferable that at least aportion of an inner wall of the storage portion that comes into contactwith the treatment liquid according to the present invention is formedof a material including at least one selected from the group consistingof polyethylene, polypropylene, polytetrafluoroethylene, andperfluoroalkoxy alkane. Here, “at least a portion” represents that, forexample, a lining, a lining layer, a laminate layer, a seal materialused for a junction portion, a lid, or an observation window in theinner wall of the storage portion may be formed another material.

In another aspect of the present invention, it is preferable that atleast a portion of the inner wall of the storage portion that comes intocontact with the treatment liquid is formed of a material including atleast one selected from the group consisting of stainless steel,HASTELLOY, INCONEL, and MONEL.

In a case where at least a portion of the inner wall of the storageportion that comes into contact with the treatment liquid formanufacturing a semiconductor according to the present invention isformed of a material including at least one selected from the groupconsisting of stainless steel, HASTELLOY, INCONEL, and MONEL, it ispreferable that the inner wall satisfies the following conditions.

That is, it is preferable that a mass ratio represented by Cr/Fe in aportion having a depth of 1 nm from an outermost surface of the innerwall is preferably in a range of 1 to 3 and more preferably in a rangeof 1 to 2.5.

The reason for this is that, in a case where the ratio Cr/Fe is in theabove-described range, an effect of suppressing the elution ofcomponents such as Fe, Ni, or Cr is high. That is, in a case where themass ratio represented by Cr/Fe is 1 or higher, the elution of Fe andthe elution of the Ni and Cr components, which occurs along with theelution of Fe, can be significantly suppressed. In addition, in a casewhere the mass ratio represented by Cr/Fe is 3 or higher, the smoothnessof the inner wall surface is maintained. Therefore, the contact area ofa chemical liquid is small, and the elution of the Fe, Ni, and Crcomponents can be more significantly suppressed. By adjusting the massratio to be 2.5 or lower, the above-described effect is moresignificant.

In the storage container according to the present invention, it ispreferable that at least the inner wall of the storage portion thatcomes into contact with the treatment liquid according to the presentinvention is cleaned using a cleaning liquid before being filled withthe treatment liquid according to the present invention.

As the cleaning liquid that can be used in a cleaning step before thefilling of the treatment liquid according to the present invention, forexample, a cleaning liquid having a contact angle of 10 degrees to 120degrees on the inner wall is preferably used.

Here, the contact angle refers to an index relating to wettability of asurface of a material with respect to a liquid and, as shown in FIG. 1 ,is expressed by an angle θ that is formed by a tangent line 13 in aperipheral portion of a liquid (cleaning liquid) 11 attached to amaterial (the inner wall of the storage portion) 10 with respect to asurface of the material 10. Accordingly, as the contact angle θincreases, the material 10 is likely to repel the liquid 11, and thewettability with respect to the liquid 11 is low. Conversely, as thecontact angle θ decreases, the material 10 is less likely to repel theliquid 11, and the wettability with respect to the liquid 11 is high.The magnitude of the contact angle θ depends on the magnitude of surfaceenergy, and as the surface energy, the contact angle θ increases.

In the present invention, the contact angle is a value measured using aθ/2 method described below in Examples.

The storage container according to the present invention is cleanedbefore being filled with the treatment liquid according to the presentinvention.

In the cleaning step before filling the storage portion with thetreatment liquid according to the present invention, by cleaning theinner wall using a cleaning liquid having a contact angle of 10 degreesor higher on the inner wall and having appropriate wettability. Thecleaning liquid does not remain in the container, and infiltration ofthe cleaning liquid filled after cleaning or contaminants included inthe cleaning liquid into the treatment liquid according to the presentinvention can be suppressed. In addition, by cleaning the inner wallusing a cleaning liquid having a contact angle of 120 degrees or loweron the inner wall and having appropriate wettability, the removal rateof contaminants remaining in fine gaps of the storage portion can beimproved.

In addition, it is preferable that the cleaning liquid includes at leastone of components included in the treatment liquid according to thepresent invention. It is preferable that the at least one component isone component or two or more components included in the treatment liquidaccording to the present invention as a major component. Requirementsfor high purity of the treatment liquid have become more strict, and thecleaning liquid itself may be an impurity in a liquid product to befilled. However, by using a cleaning liquid including the same componentas that included in the treatment liquid to be filled, the occurrence ofthe impurity can be suppressed. In one aspect of the present invention,the treatment liquid according to the present invention itself may becleaned using the cleaning liquid.

Specific examples of the cleaning liquid include ultrapure water andisopropyl alcohol. As the ultrapure water and isopropyl alcohol used asthe cleaning liquid according to the present invention, ultrapure wateror isopropyl alcohol in which the concentration of an inorganic ion suchas a sulfate ion, a chloride ion, or a nitrate ion and the concentrationof Fe, Cu, and Zn as the target metals are reduced can be used, and itis more preferable that the ultrapure water or the isopropyl alcohol isfurther reduced for use. A purification method is not particularlylimited, and purification using a filtration film or an ion-exchangemembrane or purification using distillation is preferable.

Examples of a cleaning method include a well-known method. For example,the following Example 1 and Example 2 can be used as the cleaningmethod.

Example 1

A container having an inner volume of 20 L is filled with 5 L of acleaning liquid and then is sealed. Next, by shaking the container for 1minute, the cleaning liquid is spread all over the surface of a liquidcontact portion in the container, and a lid is opened to discharge thecleaning liquid. Next, the container is rinsed with ultrapure waterthree times while replacing ultrapure water, and then is dried. Thenumber of times of cleaning using the cleaning liquid and the cleaningtime are determined according to a necessary cleanliness, and then thenumber of times of rinsing using ultrapure water and the rinsing timeare optionally determined.

Example 2

An opening of a container faces downward, and the cleaning liquid isjetted from the opening to an inner surface of the container using ajetting nozzle or the like to clean the container. In order to clean theentire inner surface of the container, for example, a method of using adiffusion nozzle, a method of disposing a plurality of nozzles, and amethod of cleaning the container while moving the container and/or acleaning nozzle are appropriately performed. The cleaning time isdetermined according to a necessary cleanliness.

In one aspect of the storage container according to the presentinvention, it is preferable that an occupancy ratio (hereinafter, alsoreferred to as “void volume”) of a void portion in the storage portionstoring the treatment liquid according to the present invention is 50 to0.01 vol %. By adjusting the upper limit value of the void volume in thestorage portion to be 50 vol % or lower, the possibility of infiltrationof impurities in gas occupying the void portion into the treatmentliquid according to the present invention can be reduced. In one aspect,the void volume in the storage portion is more preferably 20 to 0.01 vol% and still more preferably 10 to 1 vol %.

In one aspect, in the storage container according to the presentinvention, it is preferable that the void portion of the storage portionstoring the treatment liquid according to the present invention isfilled with high-purity gas having a small amount of particles. As thegas, for example, gas in which the number of particles having a diameterof 0.5 μm or more is 10 particles/L or less is preferable, and gas inwhich the number of particles having a diameter of 0.5 μm or more is 1particles/L or less is more preferable.

It is preferable that all the handling operations including thepreparing of the treatment liquid according to the present invention,the cleaning of the storage container, and the filling of the treatmentliquid, the treatment analysis, and the measurement are performed in aclean room. It is preferable that the clean room satisfies the cleanroom standards 14644-1. It is preferable that the clean room satisfiesany one of ISO Class 1, ISO Class 2, ISO Class 3, and ISO Class 4, it ismore preferable that the clean room satisfies ISO Class 1 or ISO Class2, and it is still more preferable that the clean room satisfies ISOClass 1.

In a pattern forming method or a method of manufacturing a semiconductordevice described below, the treatment liquid according to the presentinvention is used as a developer, a rinsing liquid, a pre-wet liquid, anetchant, a cleaning liquid, a peeling liquid, or the like.

That is, in the pattern forming method or the method of manufacturing asemiconductor device, the treatment liquid according to the presentinvention can be used as one treatment liquid or as two or moretreatment liquids among a developer, a rinsing liquid, a pre-wet liquid,an etchant, a cleaning liquid, and a peeling liquid.

Next, a manufacturing device that can be suitably used for manufacturingthe treatment liquid according to the present invention will bedescribed.

[Manufacturing Device]

FIG. 2 is a schematic diagram showing an aspect of a manufacturingdevice that can be used in the method of manufacturing the treatmentliquid according to the embodiment of the present invention. Themanufacturing device 100 includes a tank 101, and the tank 101 includesa supply port 102 for supplying a cleaning liquid and/or an organicsolvent (crude liquid including the treatment liquid according to thepresent invention). The manufacturing device 100 includes a filtrationdevice 105, and the tank 101 and the filtration device 105 are connectedto each other through a supply pipe 109 such that the fluid (forexample, the cleaning liquid, the organic solvent, and the treatmentliquid) can be transferred between the tank 101 and the filtrationdevice 105. In the supply pipe 109, a valve 103 and a pump 104 aredisposed. In FIG. 2 , the manufacturing device 100 includes the tank 101and the filtration device 105. However, the manufacturing device thatcan be used in the method of manufacturing the treatment liquidaccording to the embodiment of the present invention is not limited tothis configuration.

In the manufacturing device 100, the fluid supplied from the supply port102 flows to the filtration device 105 through the valve 103 and thepump 104. The fluid discharged from the filtration device 105 is storedin the tank 101 through a circulation pipe 110.

The manufacturing device 100 includes a discharge unit 111 thatdischarges the treatment liquid to the circulation pipe 110. Thedischarge unit 111 includes a valve 107 and a container 108. Byswitching between the valve 106 provided in the circulation pipe and thevalve 107, the manufactured treatment liquid can be stored in thecontainer 108. In addition, a switchable pipe 113 is connected to thevalve 107 such that the cleaning liquid can be discharged to the outsideof the manufacturing device 100 through the pipe 113 after circulationcleaning. After the circulation cleaning, the cleaning liquid mayinclude particles and metal impurities and the like. According to themanufacturing device 100 including the pipe 113 from which the cleaningliquid is discharged to the outside of the manufacturing device 100, thetreatment liquid having higher defect suppressing performance can beobtained without contamination in a filling portion and the like of thecontainer 108.

Further, the manufacturing device 100 further includes a cleaning liquidmonitoring unit 112 in the circulation pipe 110. FIG. 2 shows themanufacturing device 100 that includes the cleaning liquid monitoringunit 112 in the circulation pipe 110. However, the manufacturing devicethat can be used in the method of manufacturing the treatment liquidaccording to the embodiment of the present invention is not limited tothis configuration. The cleaning liquid monitoring unit 112 may beprovided in the supply pipe 109 or may be provided in the supply pipe109 and the circulation pipe 110. In the manufacturing device 100, thecleaning liquid monitoring unit 112 may be directly provided in thecirculation pipe 110. However, the manufacturing device that can be usedin the method of manufacturing the treatment liquid according to theembodiment of the present invention is not limited to thisconfiguration. The cleaning liquid monitoring unit may be provided in afluid temporary storage tank (not shown; different from the tank 101)provided in the pipe.

FIG. 3 is a schematic diagram showing another aspect of themanufacturing device that can be used in the method of manufacturing thetreatment liquid according to the embodiment of the present invention. Amanufacturing device 200 includes the tank 101 and the filtration device105 and further includes a distillation column 201 that is connected tothe tank 101 through a pipe 202, a pipe 204, and a pipe 203 and isdisposed such that fluid can be transferred between the tank 101 and thedistillation column 201 through the pipes. In addition, themanufacturing device that can be used in the method of manufacturing thetreatment liquid according to the embodiment of the present inventiondoes not necessarily include the filtration device 105 and/or thedistillation column 201, and may further include a reaction vesselconnected to the distillation column 201 through the pipe 203.

In the manufacturing device 200, the fluid supplied to the distillationcolumn 201 through the pipe 203 is distilled in the distillation column201. The distilled fluid is stored in the tank 101 through the pipe 202.The supply pipe 109 includes the valve 103 and a valve 206. By switchingbetween the valve 103, the valve 206, and a valve 205 provided in thepipe 204, the fluid discharged from the tank 101 can be caused to flowto the filtration device 105.

In addition, in the manufacturing device 200, the fluid discharged fromthe tank 101 can be caused to flow to the distillation column 201 again.In this case, by switching between the valve 103, the valve 206, and thevalve 205, the fluid flows from the pipe 204 to the distillation column201 through the valve 207 and the pipe 203.

A material of a liquid contact portion (the definition of the liquidcontact portion will be described below) of the manufacturing device isnot particularly limited. From the viewpoint of obtaining the treatmentliquid having higher defect suppressing performance, it is preferablethat the liquid contact portion is formed of at least one selected fromthe group consisting of a nonmetallic material and an electropolishedmetallic material. In this specification, “liquid contact portion”refers to a region (for example, a tank inner surface, a liquid feedpump, a damper, a packing, an O-ring, or a pipe inner surface) that islikely to come into contact with fluid and has a thickness of 100 nmfrom the surface.

The nonmetallic material is not particularly limited and is preferably apolyethylene resin, a polypropylene resin, a polyethylene-polypropyleneresin, or a fluorine-containing resin material. From the viewpoint ofreducing the elution of metal atoms, the nonmetallic material ispreferably a fluorine-containing resin material.

As the fluorine-containing resin material, for example, a perfluororesinis used, and examples thereof include a polytetrafluoroethylene resin(PTFE), a polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer(PFA), a polytetrafluoroethylene-hexafluoropropylene copolymer resin(FEP), a polytetrafluoroethylene-ethylene copolymer resin (ETFE), apolychlorotrifluoroethylene-ethylene copolymer resin (ECTFE), avinylidene fluoride resin (PVDF), a polychlorotrifluoroethylenecopolymer resin (PCTFE), and a vinyl fluoride resin (PVF).

Preferable examples of the fluorine-containing resin material include apolytetrafluoroethylene resin, a polytetrafluoroethylene-perfluoroalkylvinyl ether copolymer, and a polytetrafluoroethylene-hexafluoropropylenecopolymer resin.

The metallic material is not particularly limited, and a well-knownmaterial can be used.

Examples of the metallic material include a metallic material in whichthe total content of chromium and nickel is higher than 25 mass % withrespect to the total mass of the metallic material. In particular, ametallic material in which the total content of chromium and nickel is30 mass % or higher with respect to the total mass of the metallicmaterial is more preferable. The upper limit value of the total contentof chromium and nickel in the metallic material is not particularlylimited and, in general, is preferably 90 mass % or lower.

Examples of the metallic material include stainless steel, carbon steel,alloy steel, nickel-chromium-molybdenum steel, chromium steel,chromium-molybdenum steel, manganese steel, and a nickel-chromium alloy.

The stainless steel is not particularly limited, and a stainless steelcan be used. An alloy including 8 mass % or higher of nickel ispreferable, and an austenite stainless steel including 8 mass % orhigher of nickel is more preferable. Examples of the austenite stainlesssteel include SUS (Steel use Stainless) 304 (Ni content: 8 mass %, Crcontent: 18 mass %), SUS304L (Ni content: 9 mass %, Cr content: 18 mass%), SUS316 (Ni content: 10 mass %, Cr content: 16 mass %), and SUS316L(Ni content: 12 mass %, Cr content: 16 mass %).

The nickel-chromium alloy is not particularly limited, and a well-knownnickel-chromium alloy can be used. In particular, a nickel-chromiumalloy in which the nickel content is 40 to 75 mass % and the chromiumcontent is 1 to 30 mass % is preferable.

Examples of the nickel-chromium alloy include HASTELLOY (trade name;hereinafter the same shall be applied), MONEL (trade name; hereinafterthe same shall be applied), and INCONEL (trade name; hereinafter thesame shall be applied). Specific examples include HASTELLOY C-276 (Nicontent: 63 mass %, Cr content: 16 mass %), HASTELLOY-C(Ni content: 60mass %, Cr content: 17 mass %), and HASTELLOY C-22 (Ni content: 61 mass%, Cr content: 22 mass %).

In addition, optionally, the nickel-chromium alloy may further includeboron, silicon, tungsten, molybdenum, copper, and cobalt in addition tothe above-described alloy.

A method of electropolishing the metallic material is not particularlylimited, and a well-known method can be used. For example, methodsdescribed in paragraphs “0011” to “0014” of JP2015-227501A andparagraphs “0036” to “0042” of JP2008-264929A can be used.

It is presumed that, by electropolishing the metallic material, thechromium content in a passive layer of the surface is higher than thatin the parent phase. Therefore, it is presumed that since metalimpurities including metal atoms in the organic solvent are not likelyto flow out from the distillation column in which the liquid contactportion is formed of the electropolished metallic material, thedistilled organic solvent in which the impurity content is reduced canbe obtained.

The metallic material may be buffed. A buffing method is notparticularly limited, and a well-known method can be used. The size ofabrasive grains used for buffing is not particularly limited and ispreferably #400 or less from the viewpoint of further reducing theroughness of the surface of the metallic material. It is preferable thatbuffing is performed before electropolishing.

From the viewpoint of obtaining the treatment liquid having higherdefect suppressing performance, it is preferable that the liquid contactportion is formed of electropolished stainless steel. In particular, ina case where the manufacturing device includes a tank, it is morepreferable that the liquid contact portion of the tank is formed ofelectropolished stainless steel. A content mass ratio (hereinafter, alsoreferred to as “Cr/Fe”) of the Cr content to the Fe content in theliquid contact portion is not particularly limited and, in general, ispreferably 0.5 to 4. In particular, from the viewpoint of furthersuppressing the elution of metal impurities and/or organic impurities inthe treatment liquid, the content mass ratio is more preferably higherthan 0.5 and lower than 3.5 and more preferably 0.7 to 3.0. In a casewhere Cr/Fe is higher than 0.5, the metal elution from the tank can besuppressed. In a case where Cr/Fe is lower than 3.5, the peeling of theliquid contact portion or the like which causes the formation ofparticles is not likely to occur.

A method of adjusting Cr/Fe in the metallic material is not particularlylimited, and examples thereof include a method of adjusting the contentof Cr atoms in the metallic material and a method of electropolishingthe metallic material such that the chromium content in a passive layerof the surface is higher than that in the parent phase.

The metallic material may be a metallic material applied to the coatingtechniques.

The coating techniques are roughly classified into three kinds:metalcoating (various kinds of plating); inorganic coating (for example,various kinds of chemical conversion coating, glass coating, concretecoating, or ceramic coating); and organic coating (rust-preventing oilcoating, paint coating, rubber coating, or plastic coating), and any oneof the coating techniques may be adopted.

Preferable examples of the coating technique include a surface treatmentusing rust-preventing oil, a rust-preventing agent, a corrosioninhibitor, a chelate compound, a strippable plastic, or a lining agent.

In particular, as the coating technique, a surface treatment using acorrosion inhibitor, a chelate compound, or a lining agent ispreferable. Here, examples of the corrosion inhibitor include variouschromates, a nitrite, a silicate, a phosphate, a carboxylic acid (forexample, oleic acid, dimer acid, or naphthenic acid), a metal soap of acarboxylic acid, a sulfonate, an amine salt, and an ester (a glycerinester or a phosphoric acid ester of higher fatty acid). Examples of thechelate compound include ethylenediaminetetraacetic acid, gluconic acid,nitrilotriacetic acid, hydroxyethyl ethylenediaminetriacetic acid, anddiethylenediaminepentaacetic acid. Examples of the lining agent includea fluororesin lining agent. A treatment using a phosphate or fluororesinlining agent is more preferable.

By the manufacturing device including the filtration device 105, thetreatment liquid having higher defect suppressing performance can beeasily obtained. A filtration member included in the filtration device105 is not particularly limited and is preferably at least one selectedfrom the group consisting of a filter having a critical particlediameter of 20 nm or less and a metal ion adsorption filter and morepreferably a metal ion adsorption filter having a critical particlediameter of 20 nm or less.

Filter having Critical Particle Diameter of 20 nm or Less

The filter having a critical particle diameter of 20 nm or less has afunction of efficiently removing particles having a particle size of 20nm or more from the organic solvent and the like which are the rawmaterials of the treatment liquid.

The critical particle diameter of the filter is preferably 1 to 15 nmand more preferably 1 to 12 nm. In a case where the critical particlediameter is 15 nm or less, finer particles can be removed. In a casewhere the critical particle diameter is 1 nm or more, the filtrationefficiency is improved.

Here, the critical particle diameter refers to the minimum size ofparticles that can be removed by a filter. For example, in a case wherethe critical particle diameter of the filter is 20 nm, particles havinga diameter of 20 nm or more can be removed.

Examples of a material of the filter include a nylon such as 6-nylon or6,6-nylon, polyethylene, polypropylene, polystyrene, polyimide,polyamide imide, and a fluororesin. Polyimide and/or polyamide imide mayhave at least one selected from the group consisting of a carboxy group,a salt type carboxy group, and an —NH— bond. From the viewpoint ofsolvent resistance, a fluororesin or polyimide and/or polyamide imide ispreferable. In addition, from the viewpoint of adsorbing metal ions, anylon such as 6-nylon or 6,6-nylon is more preferable.

The filtration device 105 may include a plurality of filters. In a casewhere the filtration device 105 includes a plurality of filters, anotherfilter is not particularly limited and is preferably a filter having acritical particle diameter of 50 nm or more (for example, a microfiltermembrane for removing fine particles having a pore size of 50 nm ormore). In a case where fine particles are present in a material to bepurified in addition to the colloidal impurities, in particular,including metal atoms such as iron or aluminum, the material to bepurified is filtered using a filter having a critical particle diameterof 50 nm or more (for example, a microfilter membrane for removing fineparticles having a pore size of 50 nm or more) before being filteredusing a filter having a critical particle diameter of 20 nm or less (forexample, a microfilter membrane for removing fine particles having apore size of 20 nm or less). As a result, the filtration efficiency ofthe filter having a critical particle diameter of 20 nm or less (forexample, a microfilter membrane for removing fine particles having apore size of 20 nm or less) is improved, and the performance of removingparticles is further improved.

Metal Ion Adsorption Filter

It is preferable that the filtration device 105 includes the metal ionadsorption filter.

The metal ion adsorption filter is not particularly limited and, forexample, a well-known metal ion adsorption filter can be used.

In particular, an ion exchangeable filter is preferable as the metal ionadsorption filter. Here, metal ions as an adsorption target are notparticularly limited. From the viewpoint of causing defects of asemiconductor device to occur, metal ions including one selected fromFe, Cr, Ni, and Pb are preferable, and ions of metals including each ofFe, Cr, Ni, and Pb are more preferable.

From the viewpoint of improving the adsorption performance of the metalions, it is preferable that the metal ion adsorption filter has an acidgroup on the surface. Examples of the acid group include a sulfo groupand a carboxy group.

Examples of a substrate (material) forming the metal ion adsorptionfilter include cellulose, diatom earth, nylon, polyethylene,polypropylene, polystyrene, and a fluororesin. From the viewpoint ofimproving the adsorption efficiency of the metal ions, nylon is morepreferable.

In addition, the metal ion adsorption filter may be formed of a materialincluding polyimide and/or polyamide imide. Examples of the metal ionadsorption filter include polyimide and/or polyamide imide porousmembrane described in JP2016-155121A.

The Polyimide and/or polyamide imide porous membrane may have at leastone selected from the group consisting of a carboxy group, a salt typecarboxy group, and an —NH—0 bond. In a case where the metal ionadsorption filter is formed of a fluororesin, polyimide, and/orpolyamide imide, higher solvent resistance can be obtained.

Organic Impurity Adsorption Filter

The filtration device 105 may further include an organic impurityadsorption filter.

The organic impurity adsorption filter is not particularly limited and,for example, a well-known organic impurity adsorption filter can beused.

In particular, from the viewpoint of improving the adsorptionperformance organic impurities, it is preferable that the organicimpurity adsorption filter has an organic skeleton that is interactivewith organic impurities on the surface (in other words, the surface ismodified with an organic skeleton that is interactive with organicimpurities). Examples of the organic skeleton that is interactive withorganic impurities include a chemical structure that reacts with organicimpurities such that the organic impurities can be trapped in theorganic impurity adsorption filter. More specifically, in a case wherean n-long chain alkyl alcohol (for example, a structural isomer in acase where l-long chain alkyl alcohol is used as the organic solvent) isincluded as an organic impurity, examples of the organic skeletoninclude an alkyl group. In addition, in a case where a dibutyl hydroxytoluene (BHT) is included as an organic impurity, examples of theorganic skeleton include a phenyl group.

Examples of a substrate (material) forming the organic impurityadsorption filter include cellulose on which activated carbon issupported, diatom earth, nylon, polyethylene, polypropylene,polystyrene, and a fluororesin.

In addition, as the organic impurity adsorption filter, a filter inwhich activated carbon adheres to non-woven fabric described inJP2002-273123A and JP2013-150979A can also be used.

The organic impurity adsorption filter is also applicable to a physicaladsorption method as well as the above-described chemical adsorption(adsorption using the organic impurity adsorption filter having anorganic skeleton that is interactive with organic impurities on thesurface).

For example, in a case where BHT is included in as an organic impurity,the structure of BHT is larger than 10 ongstrom (=1 nm). Therefore, byusing an organic impurity adsorption filter having a pore size of 1 nm,BHT cannot pass through the pore of the filter. That is, BHT isphysically trapped in the filter, and thus is removed from the materialto be purified. This way, the organic impurities can also be removed byusing the physical removal method as well as the chemical interaction.However, in this case, a filter having a pore size of 3 nm or more isused as the “particle removal filter”, and a filter having a pore sizeof less than 3 nm is used as the organic impurity adsorption filter.

As described above, a combination of different filters may be used. Atthis time, the filtering using a first filter may be performed once, ortwice or more. In a case where filtering is performed two or more timesusing different filters in combination, the filters may be the same asor different from each other but are preferably different from eachother. Typically, it is preferable that a first filter and a secondfilter are different from each other in at least one of a pore size or aforming material.

It is preferable that the pore size of the filter used for the second orsubsequent filtering is equal to or less than that of the filter usedfor the first filtering. In addition, a combination of first filtershaving different pore sizes in the above-described range may be used.Here, the pore size of the filter can refer to a nominal value of amanufacturer of the filter. A commercially available filter can beselected from various filters manufactured by Pall Corporation, ToyoRoshi Kaisha, Ltd., Entegris Japan Co., Ltd. (former MykrolisCorporation), or Kits Microfilter Corporation. In addition, “P-NylonFilter (formed of polyamide, pore size: 0.02 μm, critical surfacetension: 77 mN/m)” (manufactured by Pall Corporation), “PE Clean Filter(formed of high-density polyethylene, pore size: 0.02 μm)” (manufacturedby Pall Corporation), or “PE Clean Filter (formed of high-densitypolyethylene, pore size: 0.01 μm)” (manufactured by Pall Corporation)can also be used.

The method of manufacturing the treatment liquid according to theembodiment of the present invention may include a step of cleaning themanufacturing device using the cleaning liquid. In this method, thecleaning liquid is supplied from the supply port 102 of the tank 101.The supply amount of the cleaning liquid is not particularly limited andis preferably adjusted such that the liquid contact portion of the tank101 can be sufficiently cleaned. The volume of the cleaning liquidsupplied is preferably 30 vol % or higher with respect to the volume ofthe tank 101. In a case where the cleaning liquid is supplied from thesupply port 102, the valve 103 may be closed or opened. However, fromthe viewpoint of more easily cleaning the tank 101, in a case where thecleaning liquid is supplied from the supply port 102, it is preferablethat the valve 103 is closed.

The cleaning liquid supplied to the tank 101 may be transferredimmediately into the manufacturing device, or may be transferred intothe manufacturing device (for example, through the supply pipe 109)after cleaning the inside of the tank 101. A method of cleaning theinside of the tank 101 using the cleaning liquid is not particularlylimited, and examples thereof include a method of cleaning the inside ofthe tank 101 by rotating stirring blades (not shown) included in thetank 101. The time during which the tank is cleaned using the cleaningliquid is not particularly limited and may be appropriately selectedaccording to the material of the liquid contact portion of the tank 101,the kind of the treatment liquid to be manufactured, the possibility ofcontamination, and the like. In general, the time is preferably about0.1 seconds to 48 hours. In a case where only the tank 101 is cleaned,the cleaning liquid after cleaning may be discharged from, for example,a discharge port (not shown) provided in the tank bottom portion.

A method of cleaning the supply pipe 109 and the like of themanufacturing device 100 using the cleaning liquid is not particularlylimited, and a method (hereinafter, also referred to as “circulationcleaning”) of circulating the cleaning liquid in the manufacturingdevice through the supply pipe 109 and the circulation pipe 110 byoperating the pump 104 in a state where the valve 103 and the valve 106are opened and the valve 107 is closed is preferable. With theabove-described method, while transferring the cleaning liquid, foreignmatters and the like attached to the liquid contact portions of the tank101, the filtration device 105, the supply pipe 109, and the like can beefficiently dispersed and/or can be efficiently dissolved using thecleaning liquid.

In particular, in a case where the manufacturing device includes thefiltration device, the circulation cleaning is more preferable as thecleaning method. An example of the circulation cleaning will bedescribed using FIG. 2 . First, the cleaning liquid supplied from thetank 101 into the manufacturing device through the valve 103 returns(circulates) to the tank 101 again through the supply pipe 109 (throughthe filtration device 105, the circulation pipe 110, and the valve 106).At this time, the cleaning liquid is filtered through the filtrationdevice 105 such that particles and the like dissolved and dispersed inthe cleaning liquid are removed and the cleaning effect can be furtherimproved.

In another aspect of the cleaning method, for example, another methodmay be used, the method including: causing the cleaning liquid suppliedfrom the supply port 102 of the tank 101 into the manufacturing deviceto flow into the filtration device 105 through the valve 103 and thepump 104 by operating the pump 104 in a state where the valve 103 andthe valve 107 are opened and the valve 106 is closed; and dischargingthe cleaning liquid to the outside of the manufacturing device throughthe valve 107 without being circulated (in this specification,hereinafter, this method will also be referred to as “batch cleaning”).In this case, as described above, the cleaning liquid may be suppliedintermittently into the manufacturing device in a predetermined amount,or may be supplied continuously into the manufacturing device.

(Cleaning Liquid)

The cleaning liquid used for performing cleaning in advance as describedabove is not particularly limited, and a well-known cleaning liquid canbe used.

Examples of the cleaning liquid include water, alkylene glycol monoalkylether carboxylate, alkylene glycol monoalkyl ether, alkyl lactate, alkylalkoxy propionate, a cyclic lactone (preferably having 4 to 10 carbonatoms), a monoketone compound (preferably having 4 to 10 carbon atoms)which may include a ring, alkylene carbonate, alkyl alkoxy acetate, andalkyl pyruvate.

In addition, as the cleaning liquid, for example, cleaning liquidsdescribed in JP2016-57614A, JP2014-219664A, JP2016-138219A, andJP2015-135379A may be used.

It is preferable that the cleaning liquid includes at least one selectedfrom the group consisting of propylene glycol monomethyl ether (PGME),cyclopentanone (CyPe), butyl acetate (nBA), propylene glycol monomethylether acetate (PGMEA), cyclohexanone (CyHx), ethyl lactate (EL), methyl2-hydroxyisobutyrate (HBM), cyclopentanone dimethylacetal (DBCPN),γ-butyrolactone (GBL), dimethyl sulfoxide (DMSO), ethylene carbonate(EC), propylene carbonate (PC), 1-methyl-2-pyrrolidone (NMP), isoamylacetate (iAA), isopropanol (IPA), methyl ethyl ketone (MEK), and4-methyl-2-pentanol (MIBC) is preferable, it is more preferable thecleaning liquid includes at least one selected from the group consistingof PGMEA, NMP, PGME, nBA, PC, CyHx, GBL, MIBC, EL, DMSO, iAA, MEK, PC,and CyPe, and it is still more preferable the cleaning liquid is formedof at least one selected from the group consisting of PGMEA, NMP, PGME,nBA, PC, CyHx, GBL, MIBC, EL, DMSO, iAA, MEK, PC, and CyPe.

As the cleaning liquid, one kind may be used alone, or two or more kindsmay be used in combination.

Examples of the cleaning liquid other than the above-described examplesinclude an alcohol such as methanol, ethanol, propanol, butanol,methoxyethanol, butoxyethanol, methoxypropanol, or ethoxypropanol; aketone such as acetone or methyl ethyl ketone, an ether such astetrahydrofuran, dioxane, ethylene glycol dimethyl ether, or diethyleneglycol dimethyl ether; an ester such as ethyl acetate or ethylcellosolve acetate; an aromatic compound such as benzene, toluene, orxylene; and a chlorinated hydrocarbon such as dichloromethane,dichloroethane, dichloroethylene, or trichloroethylene.

[Use of Treatment Liquid]

The treatment liquid according to the present invention is preferablyused for manufacturing a semiconductor. Specifically, in manufacturingsteps of a semiconductor device including a lithography step, an etchingstep, an ion implantation step, and a peeling step, the treatment liquidis used for treating an organic matter after the end of each step orbefore the start of the next step, and specifically is suitably used asa pre-wet liquid, a developer, a rinsing liquid, a peeling liquid, orthe like. For example, the treatment liquid can also be used for rinsingan edge line of a semiconductor substrate before and after resistapplication.

In addition, the treatment liquid can also be used as a dilute solutionof a resin included in a resist solution (described below). That is, thetreatment liquid can also be used as the solvent included in the actinicray-sensitive or radiation-sensitive composition.

In addition, the treatment liquid can also be suitably used for otherapplications other than the manufacturing of a semiconductor, and can beused, for example, as a developer such as polyimide, a resist for asensor, or a resist for a lens, or a rinsing liquid.

In addition, the treatment liquid can also be used for medicalapplications or as a solvent for cleaning. In particular, the treatmentliquid can be suitably used for cleaning a container, a pipe, asubstrate (for example, a wafer or glass), or the like.

<Pattern Forming Method>

The pattern forming method according to the present invention includes:a resist film forming step of applying an actinic ray-sensitive orradiation-sensitive composition (hereinafter, also referred to as“resist composition”) to a substrate to form an actinic ray-sensitive orradiation-sensitive film (hereinafter, also referred to as “resistfilm”); an exposure step of exposing the resist film; and a treatmentstep of treating the substrate to which the resist composition isapplied or the exposed resist film using the above-described treatmentliquid.

Hereinafter, each of the steps included in the pattern forming methodaccording to the present invention will be described. In addition, as anexample of the treatment step using the treatment liquid according tothe present invention, each of a pre-wet step, a development step, and arinsing step will be described.

<Pre-Wet Step>

In order to improve coating properties, the pattern forming methodaccording to the present invention may include a pre-wet step ofapplying a pre-wet liquid to the substrate in advance before the step offorming the resist film using the actinic ray-sensitive orradiation-sensitive composition. The pre-wet step is described inJP2014-220301A, the content of which is incorporated herein byreference.

<Resist Film Forming Step>

The resist film forming step is a step of forming a resist film using anactinic ray-sensitive or radiation-sensitive composition and, forexample, can be performed using the following method.

In order to form the resist film (actinic ray-sensitive orradiation-sensitive composition film) on the substrate using the actinicray-sensitive or radiation-sensitive composition, respective componentsdescribed below are dissolved in a solvent to prepare an actinicray-sensitive or radiation-sensitive composition, the actinicray-sensitive or radiation-sensitive composition is optionally filteredthrough a filter and applied to the substrate. As the filter, a filterformed of polytetrafluoroethylene, polyethylene, or nylon and having apore size of preferably 0.1 μm or less, more preferably 0.05 μm or less,and still more preferably 0.03 μm or less is preferable.

The actinic ray-sensitive or radiation-sensitive composition is appliedto the substrate (for example, silicon or a silicon dioxide coating),which is used for manufacturing an integrated circuit element, using anappropriate coating method such as a method using a spinner. Next, theactinic ray-sensitive or radiation-sensitive composition is dried toform a resist film. Optionally, various underlayer films (an inorganicfilm, an organic film, or an antireflection film) may be formed belowthe resist film.

As the drying method, a method of drying heating the composition isgenerally used. Heating may be performed using means provided in atypical exposure or developing device, and may be performed using a hotplate or the like.

The heating temperature is preferably 80° C. to 180° C., more preferably80° C. to 150° C., still more preferably 80° C. to 140° C., and evenstill more preferably 80° C. to 130° C. The heating time is preferably30 to 1000 seconds, more preferably 60 to 800 seconds, and still morepreferably 60 to 600 seconds.

The thickness of the resist film is generally 200 nm or less andpreferably 100 nm or less.

For example, in order to resolve a 1:1 line-and-space pattern having asize of 30 nm or less, the thickness of a resist film to be formed ispreferably 50 nm or less. In a case where a resist film having athickness of 50 nm or less is applied to a development step describedbelow, pattern collapse is not likely to occur, and higher resolutionperformance can be obtained.

The thickness is more preferably in a range of 15 nm to 45 nm. In a casewhere the thickness is 15 nm or more, sufficient etching resistance canbe obtained. The thickness is still more preferably is in a range of 15nm to 40 nm. In a case where the thickness is in the above-describedrange, etching resistance and higher resolution performance can besimultaneously satisfied.

In the pattern forming method according to the present invention, anupper layer film (top coat film) may be formed over the resist film. Theupper layer film can be formed using, for example, an upper layerfilm-forming composition including a hydrophobic resin, an acidgenerator, and a basic compound. The upper layer film and the upperlayer film-forming composition will be described below.

<Exposure Step>

The exposure step is a step of exposing the resist film and, forexample, can be performed using the following method.

The resist film formed as described above is irradiated with an actinicray or radiation through a predetermined mask. For irradiation of anelectron beam, drawing (direct drawing) not using a mask is generallyused.

The actinic ray or radiation is not particularly limited, and examplesthereof include KrF excimer laser light, ArF excimer laser light,extreme ultraviolet (EUV) light, and an electron beam (EB). The exposuremay be immersion exposure.

<Baking>

In the pattern forming method according to the present invention, it ispreferable that baking (heating) is performed before development afterexposure. Due to the baking, a reaction of an exposed portion ispromoted, and sensitivity and a pattern shape are further improved.

The heating temperature is preferably 80° C. to 150° C., more preferably80° C. to 140° C., and still more preferably 80° C. to 130° C.

The heating time is preferably 30 to 1000 seconds, more preferably 60 to800 seconds, and still more preferably 60 to 600 seconds.

Heating may be performed using means provided in a typical exposure ordeveloping device, and may be performed using a hot plate or the like.

<Development Step>

The development step is a step of developing the exposed resist filmwith the developer.

Examples of the developing method include: a method (dipping method) ofdipping the substrate in a container filled with the developer for agiven period of time; a method (puddle method) of causing the developerto accumulate on a surface of the substrate with a surface tension andmaintaining this state for a given period of time for development; amethod (spraying method) of spraying the developer to a surface of thesubstrate; and a method (dynamic dispense method) of continuouslyjetting the developer to the substrate, which is rotating at a givenspeed, while scanning a developer jetting nozzle on the substrate at agiven speed.

In addition, a step of stopping development while replacing the solventwith another solvent may be performed after the development step.

The developing time is not particularly limited as long as it is aperiod of time where a non-exposed portion of a resin is sufficientlydissolved. The development time is typically 10 to 300 seconds andpreferably 20 to 120 seconds.

The temperature of the developer is preferably 0° C. to 50° C. and morepreferably 15° C. to 35° C.

As the developer used in the development step, the above-describedtreatment liquid is preferably used. The developer is as describedabove. In addition to the development using the treatment liquid,development using an alkali developer may be further performed(so-called double development).

<Rinsing Step>

The rinsing step is a step of performing rinsing with the rinsing liquidafter the development step.

In the rinsing step, a developed wafer is rinsed with theabove-described rinsing liquid.

A rinsing method is not particularly limited, and examples thereofinclude: a method (rotation jetting method) of continuously jetting therinsing liquid to the substrate which is rotating at a given speed; amethod (dipping method) of dipping the substrate in a container filledwith the rinsing liquid for a given period of time; and a method(spraying method) of spraying the rinsing liquid to a surface of thesubstrate. In particular, it is preferable that the rinsing step isperformed using the rotation jetting method such that the rinsedsubstrate is rotated at a rotation speed of 2000 rpm to 4000 rpm toremove the rinsing liquid from the substrate.

The rinsing time is not particularly limited and is typically 10 secondsto 300 seconds. The rising time is preferably 10 seconds to 180 secondsand most preferably 20 seconds to 120 seconds.

The temperature of the rinsing liquid is preferably 0° C. to 50° C. andmore preferably 15° C. to 35° C.

In addition, after the development or the rising, a treatment ofremoving the developer or the rinsing liquid, which is attached to thepattern, with supercritical fluid may be performed.

Further, after the development, the rinsing, or the treatment using thesupercritical fluid, heating may be performed to remove the solventremaining in the pattern. The heating temperature is not particularlylimited as long as an excellent resist pattern can be obtained, and istypically 40° C. to 160° C. The heating temperature is preferably 50° C.to 150° C. and most preferably 50° C. to 110° C. The heating time is notparticularly limited as long as an excellent resist pattern can beobtained, and is typically 15 to 300 seconds and preferably 15 to 180seconds.

As the rinsing liquid, the above-described treatment liquid ispreferably used. The description of the rinsing liquid is as describedabove.

In the pattern forming method according to the present invention, it ispreferable that at least one of a developer or a rinsing liquid is theabove-described treatment liquid.

<Actinic Ray-Sensitive or Radiation-Sensitive Composition (ResistComposition)>

Next, the actinic ray-sensitive or radiation-sensitive composition whichis preferably used in combination with the treatment liquid according tothe present invention will be described in detail.

(A) Resin

It is preferable that a resin (A) is included as the actinicray-sensitive or radiation-sensitive composition which is preferablyused in combination with the treatment liquid according to the presentinvention. The resin (A) includes at least (i) a repeating unit having agroup which is decomposed by the action of an acid to produce a carboxylgroup (may further include a repeating unit having a phenolic hydroxylgroup), or includes may at least (ii) a repeating unit having a phenolichydroxyl group.

In a case where the resin (A) includes the repeating unit having a groupwhich is decomposed by the action of an acid to produce a carboxylgroup, the solubility in an alkali developer increases and thesolubility in the organic solvent increases due to the action of anacid.

Examples of the repeating unit having a phenolic hydroxyl group includedin the resin (A) include a repeating unit represented by the followingFormula (I).

In the formula,

R₄₁, R₄₂, and R₄₃ each independently represent a hydrogen atom, an alkylgroup, a halogen atom, a cyano group, or an alkoxycarbonyl group. R₄₂may be bonded to Ar₄ to form a ring. In this case, R₄₂ represents asingle bond or an alkylene group.

X₄ represents a single bond, —COO—, or —CONR₆₄—, and R₆₄ represents ahydrogen atom or an alkyl group.

L₄ represents a single bond or an alkylene group.

Ar₄ represents a (n+1)-valent aromatic ring group, and in a case whereAr₄ is bonded to R₄₂ to form a ring, Ar₄ represents a (n+2)-valentaromatic ring group.

n represents an integer of 1 to 5.

As the alkyl group represented by R₄₁, R₄₂, and R₄₃ in Formula (I), analkyl group having 20 or less carbon atoms which may have a substituentsuch as a methyl group, an ethyl group, a propyl group, an isopropylgroup, a n-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexylgroup, an octyl group, or a dodecyl group is preferable, an alkyl grouphaving 8 or less carbon atoms is more preferable, and an alkyl grouphaving 3 or less carbon atoms is still more preferable.

In Formula (I), the cycloalkyl group represented by R₄₁, R₄₂, and R₄₃may be monocyclic or polycyclic. In particular, a monocycloalkyl grouphaving 3 to 8 carbon atoms which may have a substituent such as acyclopropyl group, a cyclopentyl group, or a cyclohexyl group ispreferable.

Examples of the halogen atom represented by R₄₁, R₄₂, and R₄₃ in Formula(I) include a fluorine atom, a chlorine atom, a bromine atom, and aniodine atom. In particular, a fluorine atom is preferable.

As the alkyl group included in the alkoxycarbonyl group represented byR₄₁, R₄₂, and R₄₃ in Formula (I), the same alkyl groups as describedabove regarding R₄₁, R₄₂, and R₄₃ are preferable.

Preferable examples of a substituent of each of the groups include analkyl group, a cycloalkyl group, an aryl group, an amino group, an amidogroup, an ureido group, a urethane group, a hydroxyl group, a carboxylgroup, a halogen atom, an alkoxy group, a thioether group, an acylgroup, an acyloxy group, an alkoxycarbonyl group, a cyano group, and anitro group. The number of carbon atoms in the substituent is preferably8 or less.

Ar₄ represents an (n+1)-valent aromatic ring group. In a case where nrepresents 1, a divalent aromatic ring group may have a substituent, andpreferable examples thereof include an arylene group having 6 to 18carbon atoms such as a phenylene group, a tolylene group, a naphthylenegroup, or an anthracenylene group; and an aromatic ring group having aheterocycle such as thiophene, furan, pyrrole, benzothiophene,benzofuran, benzopyrrole, triazine, imidazole, benzoimidazole, triazole,thiadiazole, or thiazole.

In a case where n represents an integer of 2 or more, preferablespecific examples of the (n+1)-valent aromatic ring group include groupsobtained by removing arbitrary (n−1) hydrogen atoms from the specificexamples of the above-described divalent aromatic ring groups.

The (n+1)-valent aromatic ring group may further have a substituent.

Examples of a substituent which may be included in the alkyl group, thecycloalkyl group, the alkoxycarbonyl group, the alkylene group, and the(n+1)-valent aromatic ring group include: the alkoxy groups representedby R₄₁, R₄₂, and R₄₃ in Formula (I), such as an alkyl group, a methoxygroup, an ethoxy group, a hydroxyethoxy group, a propoxy group, ahydroxypropoxy group, or a butoxy group; and an aryl group such as aphenyl group.

As an alkyl group represented by R₆₄ in —CONR₆₄— (R₆₄ represents ahydrogen atom or an alkyl group) represented by X₄, an alkyl grouphaving 20 or less carbon atoms which may have a substituent such as amethyl group, an ethyl group, a propyl group, an isopropyl group, an-butyl group, a sec-butyl group, a hexyl group, a 2-ethylhexyl group,an octyl group, or a dodecyl group is preferable, and an alkyl grouphaving 8 or less carbon atoms is more preferable.

As X₄, a single bond, —COO—, or —CONH— is preferable, and a single bondor —COO— is more preferable.

Preferable examples of the alkylene group represented by L₄ include analkylene group having 1 to 8 carbon atoms which may have a substituentsuch as a methylene group, an ethylene group, a propylene group, abutylene group, a hexylene group, or an octylene group.

As Ar₄, an aromatic ring group having 6 to 18 carbon atoms which mayhave a substituent is more preferable, and a benzene ring group, anaphthalene ring group, or a biphenylene ring group is still morepreferable.

It is preferable that the repeating unit represented by Formula (I)includes a hydroxystyrene structure. That is, it is preferable that Ar₄represents a benzene ring group.

Preferable examples of the repeating unit having a phenolic hydroxylgroup included in the resin (A) include a repeating unit represented bythe following Formula (p1).

In Formula (p1), R represents a hydrogen atom or a linear or branchedalkyl group having a halogen atom or 1 to 4 carbon atoms. A plurality ofR's may be the same as or different from each other. As R in Formula(p1), a hydrogen atom is preferable.

Ar in Formula (p1) represents an aromatic ring, and examples thereofinclude: an aromatic hydrocarbon ring having 6 to 18 carbon atoms whichmay have a substituent such as a benzene ring, a naphthalene ring, ananthracene ring, a fluorene ring, or a phenanthrene ring; and anaromatic heterocycle having a heterocycle such as a thiophene ring, afuran ring, a pyrrole ring, a benzothiophene ring, a benzofuran ring, abenzopyrrole ring, a triazine ring, an imidazole ring, a benzoimidazolering, a triazole ring, a thiadiazole ring, or a thiazole ring. Amongthese, a benzene ring is most preferable.

In Formula (p1), m represents an integer of 1 to 5 and preferably 1.

Hereinafter, specific examples of the repeating unit having a phenolichydroxyl group included in the resin (A) will be shown, but the presentinvention is not limited thereto. In the formulae, a represents 1 or 2.

The content of the repeating unit having a phenolic hydroxyl group ispreferably 0 to 50 mol %, more preferably 0 to 45 mol %, and still morepreferably 0 to 40 mol % with respect to all the repeating units of theresin (A).

The repeating unit having a group which is decomposed by the action ofan acid to produce a carboxyl group included in the resin (A) is arepeating unit having a group which is substituted with a group obtainedby a hydrogen atom being removed from a carboxyl group due todecomposition caused by the action of an acid.

Examples of the group which is removed by an acid include—C(R₃₆)(R₃₇)(R₃₈), —C(R₃₆)(R₃₇)(OR₃₉), and —C(R₀₁)(R₀₂)(OR₃₉).

In the formulae, R₃₆ to R₃₉ each independently represent an alkyl group,a cycloalkyl group, an aryl group, an aralkyl group, or an alkenylgroup. R₃₆ and R₃₇ may be bonded to each other to form a ring.

R₀₁ to R₀₂ each independently represent a hydrogen atom, an alkyl group,a cycloalkyl group, an aryl group, an aralkyl group, or an alkenylgroup.

As the repeating unit having a group which is decomposed by the actionof an acid to produce a carboxyl group included in the resin (A), arepeating unit represented by the following Formula (AI) is preferable.

In Formula (AI),

Xa₁ represents a hydrogen atom or an alkyl group which may have asubstituent.

T represents a single bond or a divalent linking group.

Rx₁ to Rx₃ each independently represent an alkyl group (linear orbranched) or a cycloalkyl group (monocyclic or polycyclic). In a casewhere all of Rx₁ to Rx₃ represent an alkyl group (linear or branched),it is preferable that at least two of Rx₁, R_(x2), and R_(x3) representa methyl group.

Two of Rx₁ to Rx₃ may be bonded to each other to form a cycloalkyl group(monocyclic or polycyclic).

Examples of the alkyl group which may have a substituent represented byXa₁ include a methyl group or a group represented by —CH₂—R₁₁. R₁₁represents a halogen atom (for example, a fluorine atom), a hydroxylgroup, or a monovalent organic group, and examples thereof include analkyl group having 5 or less carbon atoms and an acyl group having 5 orless carbon atoms. In particular, an alkyl group having 3 or less carbonatoms is preferable, and a methyl group is more preferable. In oneaspect, Xa₁ represents preferably a hydrogen atom, a methyl group, atrifluoromethyl group, or a hydroxymethyl group.

Examples of the divalent linking group represented by T include analkylene group, a —COO-Rt- group, and a —O-Rt- group. In the formula, Rtrepresents an alkylene group or a cycloalkylene group.

T represents preferably a single bond or a —COO-Rt- group. Rt representspreferably an alkylene group having 1 to 5 carbon atoms and morepreferably a —CH₂— group, a —(CH₂)₂— group, or a —(CH₂)₃— group.

As the alkyl group represented by Rx₁ to Rx₃, an alkyl group having 1 to4 carbon atoms such as a methyl group, an ethyl group, a n-propyl group,an isopropyl group, a n-butyl group, an isobutyl group, or a t-butylgroup is preferable.

As the cycloalkyl group represented by Rx₁ to Rx₃, a monocycloalkylgroup such as a cyclopentyl group or a cyclohexyl group, or apolycycloalkyl group such as a norbornyl group, a tetracyclodecanylgroup, a tetracyclododecanyl group, or an adamantyl group is preferable.

As the cycloalkyl group which is formed by two of Rx₁ to Rx₃ beingbonded to each other, a monocycloalkyl group such as a cyclopentyl groupor a cyclohexyl group, or a polycycloalkyl group such as a norbornylgroup, a tetracyclodecanyl group, a tetracyclododecanyl group, or anadamantyl group is preferable. In particular, a monocycloalkyl grouphaving 5 or 6 carbon atoms is preferable.

In the cycloalkyl group which is formed by two of Rx₁ to Rx₃ beingbonded to each other, for example, one methylene group constituting thering may be substituted with a heteroatom such as an oxygen atom or agroup having a heteroatom such as a carbonyl group.

In the repeating unit represented by Formula (AI), for example, it ispreferable that Rx represents a methyl group or an ethyl group and thatRx₂ and Rx₃ are bonded to each other to form the cycloalkyl group.

Each of the groups may have a substituent, and examples of thesubstituent include an alkyl group (having 1 to 4 carbon atoms), ahalogen atom, a hydroxyl group, an alkoxy group (having 1 to 4 carbonatoms), a carboxyl group, and an alkoxycarbonyl group (having 2 to 6carbon atoms), in which the number of carbon atoms is preferably 8 orless.

As the repeating unit represented by Formula (AI), an acid-decomposabletertiary alkyl (meth)acrylate repeating unit (a repeating unit in whichXa₁ represents a hydrogen atom or a methyl group, and T represents asingle bond) is preferable. A repeating unit in which Rx₁ to Rx₃ eachindependently represent a linear or branched alkyl group is morepreferable, and a repeating unit in which Rx₁ to Rx₃ each independentlyrepresent a linear alkyl group is still more preferable.

Hereinafter, specific examples of the repeating unit having a groupwhich is decomposed by the action of an acid to produce a carboxyl groupincluded in the resin (A) will be shown, but the present invention isnot limited thereto.

In the specific examples, Rx and Xa₁ represent a hydrogen atom, CH₃,CF₃, or CH₂OH. Rxa and Rxb each independently represent an alkyl grouphaving 1 to 4 carbon atoms. Z represents a substituent having a polargroup. In a case where a plurality of Z's are present, Z's eachindependently represent a substituent having a polar group. p represents0 or a positive integer. Examples of the substituent having a polargroup represented by Z include a linear or branched alkyl group having ahydroxyl group, a cyano group, an amino group, an alkylamido group, or asulfonamide group, or a cycloalkyl group. In particular, an alkyl grouphaving a hydroxyl group is preferable. As the branched alkyl group, anisopropyl group is preferable.

The content of the repeating unit having a group which is decomposed bythe action of an acid to produce a carboxyl group is preferably 15 to 90mol %, more preferably 20 to 90 mol %, still more preferably 25 to 80mol %, and even still more preferably 30 to 70 mol % with respect to allthe repeating units of the resin (A).

It is preferable that the resin (A) further includes a repeating unithaving a lactone group.

As the lactone group, any group having a lactone structure can be used.In particular, a group having a 5- to 7-membered lactone structure ispreferable. In this case, it is preferable that another ring structuremay be fused to group having a 5- to 7-membered lactone structure toform a bicyclo structure or a Spiro structure.

It is preferable that the resin (A) further includes a repeating unitwhich has a group having with a lactone structure represented by any oneof the following Formulae (LC1-1) to (LC1-16). In addition, the grouphaving a lactone structure may be directly bonded to a main chain. Asthe lactone structure, a group represented by Formula (LC1-1), (LC1-4),(LC1-5), (LC1-6), (LC1-13), or (LC1-14) is preferable.

The lactone structure portion may or may not have a substituent (Rb₂).Preferable examples of the substituent (Rb₂) include an alkyl grouphaving 1 to 8 carbon atoms, a cycloalkyl group having 4 to 7 carbonatoms, an alkoxy group having 1 to 8 carbon atoms, an alkoxycarbonylgroup having 1 to 8 carbon atoms, a carboxyl group, a halogen atom, ahydroxyl group, a cyano group, and an acid-decomposable group. n₂represents an integer of 0 to 4. In a case where n₂ represents 2 ormore, a plurality of Rb₂'s may be the same as or different from eachother or may be bonded to each other to form a ring.

Examples of the repeating unit which has a group having a lactonestructure represented by any one of Formulae (LC1-1) to (LC1-16) includea repeating unit represented by the following Formula (AII).

In Formula (AII), Rb₀ represents a hydrogen atom, a halogen atom, or analkyl group having 1 to 4 carbon atoms, and the alkyl group may have asubstituent.

Preferable examples of a substituent which may be included in the alkylgroup represented by Rb₀ include a hydroxyl group and a halogen atom.

Examples of the halogen atom represented by Rb₀ include a fluorine atom,a chlorine atom, a bromine atom, and an iodine atom. Rb₀ representspreferably a hydrogen atom or a methyl group.

Ab represents a single bond, an alkylene group, a divalent linking grouphaving a monocyclic or polycyclic alicyclic hydrocarbon structure, anether group, an ester group, a carbonyl group, a carboxyl group, or adivalent group including a combination thereof. In particular, a singlebond or a linking group represented by -Ab₁-CO₂— is preferable. Ab₁represents a linear or branched alkylene group or a monocyclic orpolycyclic cycloalkylene group and preferably a methylene group, anethylene group, a cyclohexylene group, an adamantylene group, or anorbornylene group.

V represents a group represented by any one of Formulae (LC1-1) to(LC1-16).

In the repeating unit which has a group having a lactone structure, anoptical isomer is present, and any optical isomer may be used. Inaddition, one optical isomer may be used alone, or a mixture of aplurality of optical isomers may be used. In a case where one opticalisomer is mainly used, the optical purity (ee) thereof is preferably 90or higher and more preferably 95 or higher.

Hereinafter, specific examples of the repeating unit which has a grouphaving a lactone structure will be shown, but the present invention isnot limited thereto.

(In the formulae, Rx represents CH₃, CH₂OH, or CF₃)

The content of the repeating unit having a lactone group is preferably 1to 65 mol %, more preferably 1 to 30 mol %, more preferably 5 to 25 mol%, and still more preferably 5 to 20 mol %, with respect to all therepeating units of the resin (A).

The resin (A) may further include a repeating unit which has an organicgroup having a polar group, in particular, a repeating unit which has analicyclic hydrocarbon structure substituted with a polar group.

As a result, substrate adhesiveness or developer affinity are improved.As the alicyclic hydrocarbon structure of the alicyclic hydrocarbonstructure substituted with a polar group, an adamantyl group, adiamantyl group, or a norbornane group is preferable. As the polargroup, a hydroxyl group or a cyano group is preferable.

Hereinafter, specific examples of the repeating unit having a polargroup will be shown, but the present invention is not limited thereto.

In a case where the resin (A) includes the repeating unit which has anorganic group having a polar group, the content thereof is preferably 1to 50 mol %, more preferably 1 to 30 mol %, still more preferably 5 to25 mol %, and even still more preferably 5 to 20 mol % with respect toall the repeating units of the resin (A).

Further, as a repeating unit other than the above-described repeatingunits, the resin (A) may include a repeating unit having a group(photoacid generating group) which generates an acid when irradiatedwith an actinic ray or radiation. In this case, it can be consideredthat the repeating unit having a photoacid generating group correspondsto a compound (B) described below that generates an acid when irradiatedwith an actinic ray or radiation.

Examples of the repeating unit include a repeating unit represented bythe following Formula (4).

R⁴¹ represents a hydrogen atom or a methyl group. L⁴¹ represents asingle bond or a divalent linking group. L⁴² represents a divalentlinking group. W represents a structural unit which is decomposed togenerate an acid at a side chain when irradiated with an actinic ray orradiation.

Hereinafter, specific examples of the repeating unit represented byFormula (4) will be shown, but the present invention is not limitedthereto.

Other examples of the repeating unit represented by Formula (4) includerepeating units described in paragraphs “0094” to “0105” ofJP2014-041327A.

In a case where the resin (A) includes the repeating unit having aphotoacid generating group, the content of the repeating unit having aphotoacid generating group is preferably 1 to 40 mol %, more preferably5 to 35 mol %, and still more preferably 5 to 30 mol % with respect toall the repeating units of the resin (A).

The resin (A) can be synthesized using an ordinary method (for example,radical polymerization). Examples of the general synthesis methodinclude: a batch polymerization method of dissolving a monomer speciesand an initiator in a solvent and heating the solution forpolymerization; and a dropping polymerization method of dropping asolution of a monomer species and an initiator dropwise to a heatedsolvent for 1 to 10 hours. Among these, a dropping polymerization methodis preferable.

Examples of the reaction solvent include: an ether such astetrahydrofuran, 1,4-dioxane, or diisopropyl ether; a ketone such asmethyl ethyl ketone or methyl isobutyl ketone; an ester solvent such asethyl acetate; an amide solvent such as dimethyl formamide ordimethylacetamide; and a solvent for dissolving an actinic ray-sensitiveor radiation-sensitive composition described below such as propyleneglycol monomethyl ether acetate, propylene glycol monomethyl ether, orcyclohexanone. It is preferable that the same solvent as that used inthe actinic ray-sensitive or radiation-sensitive composition is used forpolymerization. As a result, particle generation during storage can besuppressed.

It is preferable that the polymerization reaction is performed in aninert gas atmosphere such as nitrogen or argon. In order to initiate thepolymerization, a commercially available radical initiator (for example,an azo initiator or peroxide) is used as the polymerization initiator.As the radical initiator, an azo initiator is preferable, and examplesthereof include an azo initiator having an ester group, a cyano group,or a carboxyl group. Preferable examples of the initiator includeazobisisobutyronitrile, azobisdimethylvaleronitrile, and dimethyl2,2′-azobis(2-methylpropionate). If desired, the initiator is addedadditionally or dividedly. After completion of the reaction, thereaction product is put into a solvent, and a desired polymer iscollected using a powder or solid collecting method or the like. Thereaction concentration is 5 to 50 mass % and preferably 10 to 30 mass %.

The reaction temperature is typically 10° C. to 150° C., preferably 30°C. to 120° C., and still more preferably 60° C. to 100° C.

Examples of a method which can be used for purification include atypical method such as: a liquid-liquid extraction method in which aresidual monomer or an oligomer component is removed using a combinationof water cleaning and an appropriate solvent; a purification method in asolution state such as ultrafiltration in which substances having aspecific molecular weight or lower are extracted and removed; aredispersion method in which a residual monomer is removed by dropping aresin solution over a poor solvent to solidify the resin in the poorsolvent; and a purification method in a solid state in which a resinslurry separated by filtration is cleaned with a poor solvent.

The weight-average molecular weight of the resin (A) is preferably 1000to 200000, more preferably 3000 to 20000, and most preferably 5000 to15000 in terms of polystyrene by GPC. By adjusting the weight-averagemolecular weight to be 1000 to 200000, deterioration in heat resistanceand dry etching resistance can be prevented. In addition, deteriorationin developability and deterioration in film forming properties caused byan increase in viscosity can be prevented.

It is still more preferable that the weight-average molecular weight ofthe resin (A) is 3000 to 9500 in terms of polystyrene by GPC. Byadjusting the weight-average molecular weight to be 3000 to 9500, inparticular, a resist residue (hereinafter also referred to as “scum”) issuppressed, and a more satisfactory pattern can be formed.

The dispersity (molecular weight distribution) is typically 1 to 5,preferably 1 to 3, more preferably 1.2 to 3.0, and still more preferably1.2 to 2.0. As the dispersity decreases, the resolution and a resistshape are improved. In addition, a side wall of a resist pattern issmooth, and roughness properties are excellent.

In the actinic ray-sensitive or radiation-sensitive composition, thecontent of the resin (A) is preferably 50 to 99.9 mass % and morepreferably 60 to 99.0 mass % with respect to the total solid content ofthe actinic ray-sensitive or radiation-sensitive composition.

In addition, in the actinic ray-sensitive or radiation-sensitivecomposition, one resin (A) may be used alone, or a plurality of resins(A) may be used in combination.

In addition, the resin (A) may include a repeating unit represented bythe following Formula (VI).

In Formula (VI),

R₆₁, R₆₂, and R₆₃ each independently represent a hydrogen atom, an alkylgroup, a cycloalkyl group, a halogen atom, a cyano group, or analkoxycarbonyl group. R₆₂ may be bonded to Ar₆ to form a ring. In thiscase, R₆₂ represents a single bond or an alkylene group.

X₆ represents a single bond, —COO—, or —CONR₆₄—. R₆₄ represents ahydrogen atom or an alkyl group.

L₆ represents a single bond or an alkylene group.

Ar₆ represents a (n+1)-valent aromatic ring group, and in a case whereAr₆ is bonded to R₆₂ to form a ring, Ar₆ represents a (n+2)-valentaromatic ring group.

In a case where n represents 2 or more, Y₂'s each independentlyrepresent a hydrogen atom or a group which is removed by the action ofan acid. At least one of Y₂'s represents a group which is removed by theaction of an acid.

n represents an integer of 1 to 4.

As the group which is removed by the action of an acid represented byY₂, a structure represented by Formula (VI-A) is more preferable.

Here, L₁ and L₂ each independently represent a hydrogen atom, an alkylgroup, a cycloalkyl group, an aryl group, or a group including acombination of an alkylene group and an aryl group.

M represents a single bond or a divalent linking group.

Q represents an alkyl group, a cycloalkyl group which may have aheteroatom, an aryl group which may have a heteroatom, an amino group,an ammonium group, a mercapto group, a cyano group, or an aldehydegroup.

At least two of Q, M, and L₁ may be bonded to each other to form a ring(preferably a 5- or 6-membered ring).

It is preferable that the repeating unit represented by the formula (VI)is a repeating unit represented by the following Formula (3).

In Formula (3),

Ar₃ represents an aromatic ring group.

R₃ represents a hydrogen atom, an alkyl group, a cycloalkyl group, anaryl group, an aralkyl group, an alkoxy group, an acyl group, or aheterocyclic group.

M₃ represents a single bond or a divalent linking group.

Q₃ represents an alkyl group, a cycloalkyl group, an aryl group, or aheterocyclic group.

At least two of Q₃, M₃, and R₃ are bonded to each other to form a ring.

The aromatic ring group represented by Ar₃ is the same as Ar₆ in Formula(VI) in a case where n in Formula (VI) represents 1. In this case, aphenylene group or a naphthylene group is more preferable, and aphenylene group is still more preferable.

Hereinafter, specific examples of the repeating unit represented byFormula (VI) will be shown, but the present invention is not limitedthereto.

It is also preferable that the resin (A) includes a repeating unitrepresented by the following Formula (4).

In Formula (4),

R₄₁, R₄₂, and R₄₃ each independently represent a hydrogen atom, an alkylgroup, a cycloalkyl group. a halogen atom, a cyano group, or analkoxycarbonyl group. R₄₂ may be bonded to L₄ to form a ring. In thiscase, R₄₂ represents an alkylene group.

L₄ represents a single bond or a divalent linking group. In a case whereL₄ and R₄₂ form a ring, L₄ represents a trivalent linking group.

R₄₄ and R₄₅ represent a hydrogen atom, an alkyl group, a cycloalkylgroup, an aryl group, an aralkyl group, an alkoxy group, an acyl group,or a heterocyclic group.

M₄ represents a single bond or a divalent linking group.

Q₄ represents an alkyl group, a cycloalkyl group, an aryl group, or aheterocyclic group.

At least two of Q₄, M₄, and R₄₄ are bonded to each other to form a ring.

R₄₄ and R₄₅ have the same definition and the same preferable range as R₃in Formula (3).

M₄ has the same definition and the same preferable range as M₃ inFormula (3).

Q₄ has the same definition and the same preferable range as Q₃ inFormula (3).

Examples of a ring which is formed by at least two of Q₄, M₄, and R₄₄being bonded to each other include the ring which is formed by at leasttwo of Q₃, M₃, and R₃ being bonded to each other, and preferable rangesthereof are also the same.

Hereinafter, specific examples of the repeating unit represented byFormula (4) will be shown, but the present invention is not limitedthereto.

In addition, the resin (A) may include a repeating unit represented bythe following Formula (BZ).

In Formula (BZ), AR represents an aryl group. Rn represents an alkylgroup, a cycloalkyl group, or an aryl group. Rn and AR may be bonded toeach other to form a nonaromatic ring.

R₁ represents a hydrogen atom, an alkyl group, a cycloalkyl group, ahalogen atom, a cyano group, or an alkyloxycarbonyl group.

Hereinafter, specific examples of the repeating unit represented by theformula (BZ) will be shown, but the present invention is not limitedthereto.

As the repeating unit having an acid-decomposable group, one kind may beused alone, or two or more kinds may be used in combination.

The content of the repeating unit having an acid-decomposable group inthe resin (A) (in a case where the resin (A) includes a plurality ofrepeating units having an acid-decomposable group, the total contentthereof) is preferably 5 mol % or higher and 80 mol % or lower, morepreferably 5 mol % or higher and 75 mol % or lower, and still morepreferably 10 mol % or higher and 65 mol % or lower with respect to allthe repeating units of the resin (A).

The resin (A) may include a repeating unit represented by the followingFormula (V) or the following Formula (VI).

In the formulae,

R₆ and R₇ each independently represent a hydrogen atom, a hydroxy group,a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms,an alkoxy group or acyloxy group, a cyano group, a nitro group, an aminogroup, a halogen atom, an ester group (—OCOR or —COOR: R represents analkyl group having 1 to 6 carbon atoms or a fluorinated alkyl group), ora carboxyl group.

n₃ represents an integer of 0 to 6.

n₄ represents an integer of 0 to 4.

X₄ represents a methylene group, an oxygen atom, or a sulfur atom.

Hereinafter, specific examples of the repeating unit represented byFormula (V) or Formula (VI) will be shown, but the present invention isnot limited thereto.

The resin (A) may further include a repeating unit having a silicon atomat a side chain. Examples of the repeating unit having a silicon atom ata side chain include a (meth)acrylate repeating unit having a siliconatom and a vinyl repeating unit having a silicon atom. The repeatingunit having a silicon atom at a side chain is typically a repeating unitwhich has a group having a silicon atom at a side chain, and examples ofthe group having a silicon atom include a trimethylsilyl group, atriethylsilyl group, a triphenylsilyl group, a tricyclohexylsilyl group,a tristrimethylsilylsiloxysilyl group, a tristrimethylsilylsilyl group,a methylbistrimethylsilylsilyl group, a methylbistrimethylsilloxysilylgroup, a dimethyltrimethylsilylsilyl group, adimethyltrimethylsilloxysilyl group, a cyclic or linear polysiloxanedescribed below, and a basket-type, ladder-type, or random-typesilsesquioxane structure described below. In the formulae, R and R1 eachindependently represent a monovalent substituent. * represents a directbond.

Preferable examples of the repeating unit having the above-describedgroup include a repeating unit derived from an acrylate or methacrylatecompound having the above-described group, and a repeating unit derivedfrom a compound having the above-described group and a vinyl group.

It is preferable that the repeating unit having a silicon atom is arepeating unit having a silsesquioxane structure. As a result, excellentcollapse performance can be exhibited during the formation of anultrafine pattern (for example, line width: 50 nm or less) in which across-sectional shape has a high aspect ratio (for example, athickness/line width is 3 or more).

Examples of the silsesquioxane structure include a basket-typesilsesquioxane structure, a ladder-type silsesquioxane structure, and arandom-type silsesquioxane structure. Among these, a basket-typesilsesquioxane structure is preferable.

Here, the basket-type silsesquioxane structure refers to asilsesquioxane structure having a basket-shaped skeleton. Thebasket-type silsesquioxane structure may be a complete basket-typesilsesquioxane structure or an incomplete basket-type silsesquioxanestructure and is preferably a complete basket-type silsesquioxanestructure.

In addition, the ladder-type silsesquioxane structure refers to asilsesquioxane structure having a ladder-shaped skeleton.

In addition, the random-type silsesquioxane structure refers to asilsesquioxane structure having a random skeleton.

It is preferable that the basket-type silsesquioxane structure is asiloxane structure represented by the following Formula (S).

In Formula (S), R represents a monovalent organic group. A plurality ofR's may be the same as or different from each other.

The organic group is not particularly limited, and specific examplesthereof include a hydroxy group, a nitro group, a carboxy group, analkoxy group, an amino group, a mercapto group, a blocked mercapto group(for example, a mercapto group blocked (protected) with an acyl group),an acyl group, an imido group, a phosphino group, a phosphinyl group, asilyl group, a vinyl group, a hydrocarbon group which may have aheteroatom, a (meth)acryl group-containing group, and an epoxygroup-containing group.

Examples of the heteroatom of the hydrocarbon group which may have aheteroatom include an oxygen atom, a nitrogen atom, a sulfur atom, and aphosphorus atom.

Examples of the hydrocarbon group of the hydrocarbon group which mayhave a heteroatom include an aliphatic hydrocarbon group, an aromatichydrocarbon group, and a group including a combination thereof.

The aliphatic hydrocarbon group may be linear, branched, or cyclic.Specific examples of the aliphatic hydrocarbon group include a linear orbranched alkyl group (particularly having 1 to 30 carbon atoms), alinear or branched alkenyl group (particularly having 2 to 30 carbonatoms), and a linear or branched alkynyl group (particularly, having 2to 30 carbon atoms).

Examples of the aromatic hydrocarbon group include an aromatichydrocarbon group having 6 to 18 carbon atoms such as a phenyl group, atolyl group, a xylyl group, or a naphthyl group.

In a case where the resin (A) includes the repeating unit which hassilicon atom at a side chain, the content thereof is preferably 1 to 30mol %, more preferably 5 to 25 mol %, and still more preferably 5 to 20mol % with respect to all the repeating units of the resin (A).

(B) Compound (Photoacid Generator) which generates Acid by Actinic Rayor Radiation

It is preferable that the actinic ray-sensitive or radiation-sensitiveresin composition includes a compound (hereinafter, also referred to as“photoacid generator (PAG)”) which generates an acid by an actinic rayor radiation.

The photoacid generator may be a low molecular weight compound or may beincorporated into a part of a polymer. In addition, the photoacidgenerator may be a low molecular weight compound which is incorporatedinto a part of a polymer.

In a case where the photoacid generator is a low molecular weightcompound, the molecular weight is preferably 3000 or lower, morepreferably 2000 or lower, and still more preferably 1000 or lower.

In a case where the photoacid generator is incorporated into a part of apolymer, the photoacid generator may be incorporated into a part of theresin (A) or another resin different from the resin (A).

In the present invention, it is preferable that the photoacid generatoris a low molecular weight compound.

The photoacid generator is not particularly limited as long as it iswell-known. As the photoacid generator, a compound, which generates anorganic acid, for example, at least one of sulfonic acid,bis(alkylsulfonyl)imide, or tris(alkylsulfonyl)methide when irradiatedwith an actinic ray or radiation and preferably an electron beam or anextreme ultraviolet ray, is preferable.

A compound represented by the following Formula (ZI), (ZII) or (ZIII) ismore preferable.

In Formula (ZI),

R₂₀₁, R₂₀₂, and R₂₀₃ each independently represent an organic group.

The number of carbon atoms in the organic group represented by R₂₀₁,R₂₀₂, and R₂₀₃ is generally 1 to 30 and preferably 1 to 20.

In addition, two of R₂₀₁ to R₂₀₃ may be bonded to each other to form aring structure, and the ring may include an oxygen atom, a sulfur atom,an ester bond, an amide bond, or a carbonyl group. Examples of the groupwhich is formed by two of R₂₀₁ to R₂₀₃ being bonded to each otherinclude an alkylene group (for example, a butylene group or a pentylenegroup).

Z⁻ represents a non-nucleophilic anion (an anion having a significantlylow ability to cause a nucleophilic reaction to occur).

Examples of the non-nucleophilic anion include a sulfonate anion (forexample, an aliphatic sulfonate anion, an aromatic sulfonate anion, or acamphor sulfonate anion), a carboxylate anion (for example, an aliphaticcarboxylate anion, an aromatic carboxylate anion, or an aralkylcarboxylate anion), a sulfonyl imide anion, a bis(alkylsulfonyl)imideanion, and a tris(alkylsulfonyl)methide anion.

An aliphatic site in the aliphatic sulfonate anion and the aliphaticcarboxylate anion may be an alkyl group or a cycloalkyl group and ispreferably a linear or branched alkyl group having 1 to 30 carbon atomsor a cycloalkyl group having 3 to 30 carbon atoms.

As the aromatic group in the aromatic sulfonate anion and the aromaticcarboxylate anion, an aryl group having 6 to 14 carbon atoms ispreferable, and examples thereof include a phenyl group, a tolyl group,and naphthyl group.

The alkyl group, the cycloalkyl group, and the aryl group describedabove may have a substituent. Specific examples of the substituentinclude a nitro group, a halogen atom such as a fluorine atom, acarboxyl group, a hydroxyl group, an amino group, a cyano group, analkoxy group (preferably having 1 to 15 carbon atoms), a cycloalkylgroup (preferably having 3 to 15 carbon atoms), an aryl group(preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group(preferably having 2 to 7 carbon atoms), an acyl group (preferablyhaving 2 to 12 carbon atoms), an alkoxycarbonyloxy group (preferablyhaving 2 to 7 carbon atoms), an alkylthio group (preferably having 1 to15 carbon atoms), an alkylsulfonyl group (preferably having 1 to 15carbon atoms), an alkyliminosulfonyl group (preferably having 1 to 15carbon atoms), an aryloxysulfonyl group (preferably having 6 to 20carbon atoms), an alkylaryloxysulfonyl group (preferably having 7 to 20carbon atoms), a cycloalkylaryloxysulfonyl group (preferably having 10to 20 carbon atoms), an alkyloxyalkyloxy group (preferably having 5 to20 carbon atoms), and a cycloalkylalkyloxyalkyloxy group (preferablyhaving 8 to 20 carbon atoms).

Examples of an aryl group and a ring structure included in each of thegroups include an alkyl group (preferably having 1 to 15 carbon atoms)as a substituent.

As the aralkyl group in the aralkyl carboxylate anion, an aralkyl grouphaving 7 to 12 carbon atoms is preferable, and examples thereof includea benzyl group, a phenethyl group, a naphthylmethyl group, anaphthylethyl group, and a naphthylbutyl group.

Examples of the sulfonyl imide anion include a saccharin anion.

As the alkyl group in the bis(alkylsulfonyl)imide anion and thetris(alkylsulfonyl)methide anion, an alkyl group having 1 to 5 carbonatoms is preferable. Examples of a substituent of the alkyl groupinclude a halogen atom, an alkyl group substituted with a halogen atom,an alkoxy group, an alkylthio group, an alkyloxysulfonyl group, anaryloxysulfonyl group, and a cycloalkylaryloxysulfonyl group. Amongthese, a fluorine atom or an alkyl group substituted with a fluorineatom is preferable.

In addition, the alkyl groups in the bis(alkylsulfonyl)imide anions maybe bonded to each other to form a ring structure. As a result, the acidstrength increases.

Other examples of the non-nucleophilic anion include phosphorus fluoride(for example, PF₆ ⁻), boron fluoride (for example, BF₄ ⁻), and antimonyfluoride (for example, SbF₆ ⁻).

As the non-nucleophilic anion, an aliphatic sulfonate anion in which atleast the α-position of sulfonic acid is substituted with a fluorineatom, an aromatic sulfonate anion substituted with a fluorine atom or agroup having a fluorine atom, a bis(alkylsulfonyl)imide anion in whichthe alkyl group is substituted with a fluorine atom, or atris(alkylsulfonyl)methide anion in which the alkyl group is substitutedwith a fluorine atom is preferable. As the non-nucleophilic anion, aperfluoroaliphatic sulfonate anion (still more preferably having 4 to 8carbon atoms) or a benzenesulfonate anion having a fluorine atom is morepreferable, and a nonafluorobutanesulfonate anion, aperfluorooctanesulfonate anion, a pentafluorobenzenesulfonate anion, ora 3,5-bis(trifluoromethyl)benzenesulfonate anion is still morepreferable.

From the viewpoint of the acid strength, it is preferable that the pKaof the acid generated is −1 or lower to improve sensitivity.

In addition, as the non-nucleophilic anion, for example, an anionrepresented by the following Formula (AN1) is preferable.

In the formula,

Xf's each independently represent a fluorine atom or an alkyl groupsubstituted with at least one fluorine atom.

R¹ and R² each independently represent a hydrogen atom, a fluorine atom,or an alkyl group. In a case where a plurality of R¹'s and a pluralityof R²'s are present, R¹'s and R²'s may be the same as or different fromeach other.

L represents a divalent linking group. In a case where a plurality ofL's are present, L's may be the same as or different from each other.

A represents a cyclic organic group.

x represents an integer of 1 to 20, y represent an integer of 0 to 10,and z represents an integer of 0 to 10.

Formula (AN1) will be described in more detail.

As the alkyl group in the alkyl group substituted with a fluorine atomrepresented by Xf, an alkyl group having 1 to 10 carbon atoms ispreferable, and an alkyl group having 1 to 4 carbon atoms is morepreferable. In addition, as the alkyl group in the alkyl groupsubstituted with a fluorine atom represented by Xf, a perfluoroalkylgroup is preferable.

Xf represents preferably a fluorine atom or a perfluoroalkyl grouphaving or 1 to 4 carbon atoms. Specific examples of Xf include afluorine atom, CF₃, C₂F₅, C₃F₇, C₄F₉, CH₂CF₃, CH₂CH₂CF₃, CH₂C₂F₅,CH₂CH₂C₂F₅, CH₂C₃F₇, CH₂CH₂C₃F₇, CH₂C₄F₉, and CH₂CH₂C₄F₉. Among these, afluorine atom or CF₃ is preferable.

In particular, it is preferable that both Xf's represent a fluorineatom.

The alkyl group represented by R¹ and R² may have a substituent(preferably a fluorine atom), and an alkyl group having 1 to 4 carbonatoms is preferable. A perfluoroalkyl group having 1 to 4 carbon atomsis more preferable. Specific examples of the alkyl group having asubstituent represented by R¹ and R² include CF₃, C₂F₅, C₃F₇, C₄F₉,C₅F₁₁, C₆F₁₃, C₇F₁₅, C₈F₁₇, CH₂CF₃, CH₂CH₂CF₃, CH₂C₂F₅, CH₂CH₂C₂F₅,CH₂C₃F₇, CH₂CH₂C₃F₇, CH₂C₄F₉, and CH₂CH₂C₄F₉. Among these, CF₃ ispreferable.

R¹ and R² represent preferably a fluorine atom or CF₃.

x represents preferably 1 to 10 and more preferably 1 to 5.

y represents preferably 0 to 4 and more preferably 0.

z represents preferably 0 to 5 and more preferably 0 to 3.

The divalent linking group represented by L is not particularly limited,and examples thereof include —COO—, —OCO—, —CO—, —O—, —S—, —SO—, —SO₂—,an alkylene group, a cycloalkylene group, an alkenylene group, a linkinggroup obtained by linking two or more kinds among the above-describedgroups linking to each other. A linking group having 12 or less carbonatoms in total is preferable. Among these, —COO—, —OCO—, —CO—, or —O— ispreferable, and —COO— or —OCO— is more preferable.

In Formula (ANI), as a combination of partial structures other than A,for example, SO³⁻CF₂—CH₂—OCO—, SO³⁻—CF₂—CH₂—CHF—OCO—, SO³⁻—CF₂—OCO—,SO³⁻—CF₂—CF₂—CH₂—, or SO³⁻—CF₂—CH(CF₃)—OCO— is preferable.

The cyclic organic group represented by A is not particularly limited aslong as it has a cyclic structure, and examples thereof include analicyclic group, an aryl group, a heterocyclic group (including not onlyan aromatic heterocyclic group but also a nonaromatic heterocyclicgroup).

The alicyclic group may be monocyclic or polycyclic, and amonocycloalkyl group such as a cyclopentyl group, a cyclohexyl group, ora cyclooctyl group, or a polycycloalkyl group such as a norbornyl group,a tricyclodecanyl group, a tetracyclodecanyl group, atetracyclododecanyl group, or an adamantyl group is preferable. Amongthese, an alicyclic group having a bulky structure which has 7 or morecarbon atoms such as a norbornyl group, a tricyclodecanyl group, atetracyclodecanyl group, a tetracyclododecanyl group, or an adamantylgroup is preferable from the viewpoints of suppressing in-film diffusionin a heating step after exposure and improving a mask error enhancementfactor (MEEF).

Examples of the aryl group include a benzene ring, a naphthalene ring, aphenanthrene ring, and an anthracene ring.

Examples of the heterocyclic group include a furan ring, a thiophenering, a benzofuran ring, a benzothiophene ring, a dibenzofuran ring, adibenzothiophene ring, and a group derived from a pyridine ring. Amongthese, a furan ring, a thiophene ring, or a group derived from apyridine ring is preferable.

In addition, as the cyclic organic group, a lactone structure can beused, and specific examples thereof include lactone structuresrepresented by the following Formulae (LC1-1) to (LC1-17).

The cyclic organic group may have a substituent, and examples of thesubstituent include an alkyl group (a linear, branched, or cyclic alkylgroup; preferably having 1 to 12 carbon atoms), a cycloalkyl group (amonocycle, a polycycle, or a Spiro ring; preferably having 3 to 20carbon atoms), an aryl group (preferably having 6 to 14 carbon atoms), ahydroxy group, an alkoxy group, an ester group, an amido group, aurethane group, an ureido group, a thioether group, a sulfonamide group,and a sulfonate group. Carbon (carbon contributing to ring formation)constituting the cyclic organic group may be carbonyl carbon.

The substituent corresponds to Rb₂ in (LC1-1) to (LC1-17). In addition,in (LC1-1) to (LC1-17), n₂ represents an integer of 0 to 4. In a casewhere n₂ represents 2 or more, a plurality of Rb₂'s may be the same asor different from each other or may be bonded to each other to form aring.

Examples of the organic group represented by R₂₀₁, R₂₀₂, and R₂₀₃ inFormula (ZI) include an aryl group, an alkyl group, and a cycloalkylgroup.

It is preferable that at least one of R₂₀₁, R₂₀₂, or R₂₀₃ represents anaryl group, and it is more preferable that all of R₂₀₁, R₂₀₂, or R₂₀₃represent an aryl group. As the aryl group, not only a phenyl group or anaphthyl group but also a heteroaryl group such as an indole residue ora pyrrole residue may be used. As the alkyl group and the cycloalkylgroup represented by R₂₀₁ to R₂₀₃, a linear or branched alkyl grouphaving 1 to 10 carbon atoms or a cycloalkyl group having 3 to 10 carbonatoms is preferable. As the alkyl group, a methyl group, an ethyl group,a n-propyl group, an i-propyl group, or a n-butyl group is morepreferable. As the cycloalkyl group, a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, or a cycloheptyl groupis more preferable. Each of the groups may further have a substituent.Examples of the substituent include a nitro group, a halogen atom suchas a fluorine atom, a carboxyl group, a hydroxyl group, an amino group,a cyano group, an alkoxy group (preferably having 1 to 15 carbon atoms),a cycloalkyl group (preferably having 3 to 15 carbon atoms), an arylgroup (preferably having 6 to 14 carbon atoms), an alkoxycarbonyl group(preferably having 2 to 7 carbon atoms), an acyl group (preferablyhaving 2 to 12 carbon atoms), and an alkoxycarbonyloxy group (preferablyhaving 2 to 7 carbon atoms), but the present invention is not limitedthereto.

Next, Formulae (ZII) and (ZIII) will be described.

In Formulae (ZII) and (ZIII), R₂₀₄ to R₂₀₇ each independently representan aryl group, an alkyl group, or a cycloalkyl group.

As the aryl group represented by R₂₀₄ to R₂₀₇, a phenyl group or anaphthyl group is preferable, and a phenyl group is more preferable. Thearyl group represented by R₂₀₄ to R₂₀₇, may be an aryl group which has aheterocyclic structure having an oxygen atom, a nitrogen atom, or asulfur atom. Examples of a skeleton of the aryl group having aheterocyclic structure include pyrrole, furan, thiophene, indole,benzofuran, and benzothiophene.

Preferable examples of the alkyl group and the cycloalkyl grouprepresented by R₂₀₄ to R₂₀₇ include a linear or branched alkyl grouphaving 1 to 10 carbon atoms (for example, a methyl group, an ethylgroup, a propyl group, a butyl group or a pentyl group), and acycloalkyl group having 3 to 10 carbon atoms (a cyclopentyl group, acyclohexyl group, or a norbornyl group).

The aryl group, the alkyl group, and the cycloalkyl group represented byR₂₀₄ to R₂₀₇ may have a substituent. Examples of the substituent whichmay be included in the aryl group, the alkyl group, and the cycloalkylgroup represented by R₂₀₄ to R₂₀₇ include an alkyl group (for example,having 1 to 15 carbon atoms), a cycloalkyl group (for example, having 3to 15 carbon atoms), an aryl group (for example, having 6 to 15 carbonatoms), an alkoxy group (for example, having 1 to 15 carbon atoms), ahalogen atom, a hydroxyl group, and a phenylthio group.

In addition, Z⁻ in Formula (ZII) represents a non-nucleophilic anion.Specifically, Z⁻ in Formula (ZII) has the same definition and the samepreferable aspect as Z⁻ in Formula (ZI).

Hereinafter, specific examples of Formulae (ZI) to (ZIII) will be shownbelow, but the present invention is not limited thereto.

In the present invention, from the viewpoint of suppressing diffusion ofan acid generated by exposure to a non-exposed portion and improvingresolution, the photoacid generator is preferably a compound whichgenerates an acid (more preferably sulfonic acid) having a volume of 130Å³ or higher when irradiated with an electron beam or an extremeultraviolet ray, more preferably a compound which generates an acid(more preferably sulfonic acid) having a volume of 190 Å³ or higher,still more preferably a compound which generates an acid (morepreferably sulfonic acid) having a volume of 270 Å³ or higher, and evenstill more preferably a compound which generates an acid (morepreferably sulfonic acid) having a volume of 400 Å³ or higher. From theviewpoints of sensitivity and coating solvent solubility, the volume ispreferably 2000 Å³ or lower and more preferably 1500 Å³ or lower. Avalue of the volume is obtained using “WinMOPAC” (manufactured byFUJITSU). That is, a chemical structure of an acid according to eachexample is input. Next, the most stable conformation of each acid isdetermined through a molecular field calculation using a MM3 method withthe input chemical structure as an initial structure. Next, a molecularorbital calculation is performed on the most stable conformation using aPM3 method. As a result, “accessible volume” of each acid can becalculated.

In the present invention, the following examples of the photoacidgenerators which generate an acid when irradiated with an actinic ray orradiation are preferable. In some of the examples, a calculated value ofthe volume is added (unit: Å³). The calculated value herein denotes avalue of an acid in which a proton is bonded to the anion portion.

The details of the photoacid generator can be found in paragraphs “0368”to “0377” of JP2014-41328A and paragraphs “0240” to “0262” ofJP2013-228681A (corresponding to paragraph “0339” of US2015/004533A),the content of which is incorporated herein by reference. In addition,specific preferable examples include the following compounds, but thepresent invention is not limited thereto.

As the photoacid generator, one kind may be used alone, or two or morekinds may be used in combination.

The content of the photoacid generator in the actinic ray-sensitive orradiation-sensitive resin composition is preferably 0.1 to 50 mass %,more preferably 5 to 50 mass %, and still more preferably 8 to 40 mass %with respect to the total solid content of the composition. Inparticular, in order to simultaneously realize high sensitivity and highresolution during irradiation of an electron beam or an extremeultraviolet ray, the content of the photoacid generator is preferablyhigh, more preferably 10 to 40 mass %, and still more preferably 10 to35 mass %.

(C) Solvent

In order to dissolve the respective components to prepare the actinicray-sensitive or radiation-sensitive resin composition, a solvent can beused. Examples of the solvent used include an organic solvent such asalkylene glycol monoalkyl ether carboxylate, alkylene glycol monoalkylether, alkyl lactate, alkyl alkoxy propionate, cyclic lactone having 4to 10 carbon atoms, a monoketone compound having 4 to 10 carbon atomswhich may include a ring, alkylene carbonate, alkyl alkoxy acetate, oralkyl pyruvate. As the solvent used in the present invention, a solventin which the concentration of an inorganic ion such as a sulfate ion, achloride ion, or a nitrate ion and the concentration of Fe, Cu, and Znas the target metals are reduced can be used, and it is more preferablethat the solvent is further purified for use.

Preferable examples of the alkylene glycol monoalkyl ether carboxylateinclude propylene glycol monomethyl ether acetate, propylene glycolmonoethyl ether acetate, propylene glycol monopropyl ether acetate,propylene glycol monobutyl ether acetate, propylene glycol monomethylether propionate, propylene glycol monoethyl ether propionate, ethyleneglycol monomethyl ether acetate, and ethylene glycol monoethyl etheracetate.

Preferable examples of the alkylene glycol monoalkyl ether includepropylene glycol monomethyl ether, propylene glycol monoethyl ether,propylene glycol monopropyl ether, propylene glycol monobutyl ether,ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether.

Preferable examples of the alkyl lactate include methyl lactate, ethyllactate, propyl lactate, and butyl lactate.

Preferable examples of the alkyl alkoxy propionate include ethyl3-ethoxypropionate, methyl 3-methoxypropionate, methyl3-ethoxypropionate, and ethyl 3-methoxypropionate.

Preferable examples of the cyclic lactone having 4 to 10 carbon atomsinclude β-propiolactone, β-butyrolactone, γ-butyrolactone,α-methyl-γ-butyrolactone, β-methyl-γ-butyrolactone, γ-valerolactone,γ-caprolactone, γ-octanoic lactone, and α-hydroxy-γ-butyrolactone.

Preferable examples of the monoketone compound having 4 to 10 carbonatoms which may include a ring include 2-butanone, 3-methylbutanone,pinacolone, 2-pentanone, 3-pentanone, 3-methyl-2-pentanone,4-methyl-2-pentanone, 2-methyl-3-pentanone, 4,4-dimethyl-2-pentanone,2,4-dimethyl-3-pentanone, 2,2,4,4-tetramethyl-3-pentanone, 2-hexanone,3-hexanone, 5-methyl-3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone,2-methyl-3-heptanone, 5-methyl-3-heptanone, 2,6-dimethyl-4-heptanone,2-octanone, 3-octanone, 2-nonanone, 3-nonanone, 5-nonanone, 2-decanone,3-decanone, 4-decanone, 5-hexen-2-one, 3-penten-2-one, cyclopentanone,2-methylcyclopentanone, 3-methylcyclopentanone,2,2-dimethylcyclopentanone, 2,4,4-trimethylcyclopentanone,cyclohexanone, 3-methylcyclohexanone, 4-methylcyclohexanone,4-ethylcyclohexanone, 2,2-dimethylcyclohexanone,2,6-dimethylcyclohexanone, 2,2,6-trimethylcyclohexanone, cycloheptanone,2-methylcycloheptanone, and 3-methylcycloheptanone.

Preferable examples of the alkylene carbonate include propylenecarbonate, vinylene carbonate, ethylene carbonate, and butylenecarbonate.

Preferable examples of the alkyl alkoxy acetate include 2-methoxyethylacetate, 2-ethoxyethyl acetate, 2-(2-ethoxyethoxy)ethyl acetate,3-methoxy-3-methylbutyl acetate, and 1-methoxy-2-propyl acetate.

Preferable examples of the alkyl pyruvate include methyl pyruvate, ethylpyruvate, and propyl pyruvate.

Preferable examples of the solvent which can be used include a solventhaving a boiling point of 130° C. or higher at a normal temperatureunder a normal pressure. Specific examples of the solvent includecyclopentanone, γ-butyrolactone, cyclohexanone, ethyl lactate, ethyleneglycol monoethyl ether acetate, propylene glycol monomethyl etheracetate, ethyl 3-ethoxypropionate, ethyl pyruvate, 2-ethoxyethylacetate, 2-(2-ethoxyethoxy)ethyl acetate, and propylene carbonate.

In the present invention, as the solvent, one kind may be used alone, ortwo or more kinds may be used in combination.

In the present invention, as the organic solvent, a mixed solvent inwhich a solvent having a hydroxyl group in a structure is mixed with asolvent having no hydroxyl group may be used.

Examples of the solvent having a hydroxyl group include ethylene glycol,ethylene glycol monomethyl ether, ethylene glycol monoethyl ether,propylene glycol, propylene glycol monomethyl ether, propylene glycolmonoethyl ether, and ethyl lactate. Among these, propylene glycolmonomethyl ether or ethyl lactate is preferable.

Examples of the solvent having no hydroxyl group include propyleneglycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone,γ-butyrolactone, cyclohexanone, butyl acetate, N-methylpyrrolidone,N,N-dimethylacetamide, and dimethyl sulfoxide. Among these, propyleneglycol monomethyl ether acetate, ethyl ethoxypropionate, 2-heptanone,γ-butyrolactone, cyclohexanone, or butyl acetate is more preferable, andpropylene glycol monomethyl ether acetate, ethyl ethoxypropionate,2-heptanone is most preferable.

A mixing ratio (mass) of the solvent having a hydroxyl group to thesolvent having no hydroxyl group is preferably 1/99 to 99/1, morepreferably 10/90 to 90/10, and still more preferably 20/80 to 60/40 bymass. In particular, a mixed solvent including 50 mass % or higher ofthe solvent having no hydroxyl group is preferable from the viewpoint ofcoating uniformity.

It is preferable that the solvent is a mixed solvent including two ormore propylene glycol monomethyl ether acetates.

As the solvent, for example, a solvent described in paragraphs “0013” to“0029” of JP2014-219664A can also be used.

(D) Basic Compound

In order to reduce a change in performance with the lapse of time fromexposure to heating, it is preferable that the actinic ray-sensitive orradiation-sensitive resin composition includes a basic compound (D).

Preferable examples of the basic compound (D) include compounds havingstructures represented by the following Formulae (A) to (E).

In Formulae (A) and (E), R²⁰⁰, R²⁰¹, and R²⁰² may be the same as ordifferent from each other and each independently represent a hydrogenatom, an alkyl group (preferably having 1 to 20 carbon atoms), acycloalkyl group (preferably having 3 to 20 carbon atoms), or an arylgroup (preferably having 6 to 20 carbon atoms). Here, R²⁰¹ and R²⁰² maybe bonded to each other to form a ring.

As the alkyl group having a substituent, an aminoalkyl group having 1 to20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, or acyanoalkyl group having 1 to 20 carbon atoms is preferable.

R²⁰³, R²⁰⁴, R²⁰⁵, and R²⁰⁶ may be the same as or different from eachother and each independently represent an alkyl group having 1 to 20carbon atoms.

It is more preferable that the alkyl group in the Formulae (A) and (E)is unsubstituted.

Examples of a preferable compound include guanidine, aminopyrrolidine,pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine,and piperidine. Examples of a more preferable compound include acompound having an imidazole structure, a diazabicyclo structure, anonium hydroxide structure, an onium carboxylate structure, atrialkylamine structure, an aniline structure, or a pyridine structure,an alkylamino derivative having a hydroxyl group and/or an ether bond,and an aniline derivative having a hydroxyl group and/or an ether bond.

Examples of the compound having an imidazole structure includeimidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of thecompound having a diazabicyclo structure include 1,4-diazabicyclo[2,2,2]octane, 1,5-diazabicyclo [4,3,0]nona-5-ene, and 1,8-diazabicyclo[5,4,0]undeca-7-ene. As the compound having an onium hydroxidestructure, for example, triarylsulfonium hydroxide, phenacyl sulfoniumhydroxide, or sulfonium hydroxide having a 2-oxoalkyl group can be used,and specific examples thereof include triphenylsulfonium hydroxide,tris(t-butylphenyl)sulfonium hydroxide, bis(t-butylphenyl)iodoniumhydroxide, phenacyl thiophenium hydroxide, and 2-oxopropylthiopheniumhydroxide. As the compound having an onium carboxylate structure, forexample, a compound obtained by carboxylation of the anion site of acompound having an omnium hydroxide structure can be used, and examplesthereof include acetate, adamantane-1-carboxylate, and perfluoroalkylcarboxylate. Examples of the compound having trialkylamine structureinclude tri-(n-butyl)amine and tri-(n-octyl)amine. Examples of thecompound having an aniline structure include 2,6-diisopropylaniline,N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline.Examples of the alkylamino derivative having a hydroxyl group and/or anether bond include ethanolamine, diethanolamine, triethanolamine, andtris(methoxyethoxyethyl)amine. Examples of the aniline derivative havinga hydroxyl group and/or an ether bond includeN,N-bis(hydroxyethyl)aniline.

Other preferable examples of the basic compound include an aminecompound having a phenoxy group and an ammonium salt compound having aphenoxy group.

As the amine compound, a primary, secondary, or tertiary amine compoundcan be used, and an amine compound in which at least one alkyl group isbonded to a nitrogen atom is preferable. It is more preferable that theamine compound is a tertiary amine compound. In the amine compound, aslong as at least one alkyl group (preferably having 1 to 20 carbonatoms) is bonded to a nitrogen atom, in addition to the alkyl group, acycloalkyl group (preferably having 3 to 20 carbon atoms) or an arylgroup (preferably 6 to 12 carbon atoms) may be bonded to a nitrogenatom.

In addition, it is preferable that the amine compound has an oxygen atomat an alkyl chain to form an oxyalkylene group. The number ofoxyalkylene groups is 1 or more, preferably 3 to 9, and still morepreferably 4 to 6 in a molecule. Among the oxyalkylene groups, anoxyethylene group (—CH₂CH₂O—) or an oxypropylene group (—CH(CH₃)CH₂O— or—CH₂CH₂CH₂O—) is preferable, and an oxyethylene group is morepreferable.

As the ammonium salt compound, a primary, secondary, tertiary, orquaternary ammonium salt compound can be used, and an ammonium saltcompound in which at least one alkyl group is bonded to a nitrogen atomis preferable. In the ammonium salt compound, as long as at least onealkyl group (preferably having 1 to 20 carbon atoms) is bonded to anitrogen atom, in addition to the alkyl group, a cycloalkyl group(preferably having 3 to 20 carbon atoms) or an aryl group (preferably 6to 12 carbon atoms) may be bonded to a nitrogen atom.

In addition, it is preferable that the ammonium salt compound has anoxygen atom at an alkyl chain to form an oxyalkylene group. The numberof oxyalkylene groups is 1 or more, preferably 3 to 9, and still morepreferably 4 to 6 in a molecule. Among the oxyalkylene groups, anoxyethylene group (—CH₂CH₂O—) or an oxypropylene group (—CH(CH₃)CH₂O- or—CH₂CH₂CH₂O—) is preferable, and an oxyethylene group is morepreferable.

Examples of an anion of the ammonium salt compound include a halogenatom, a sulfonate, a borate, and a phosphate. Among these, a halogenatom or a sulfonate is preferable. As the halogen atom, a chloride, abromide, or an iodide is preferable. As the sulfonate, an organicsulfonate having 1 to 20 carbon atoms is preferable. Examples of theorganic sulfonate include an alkyl sulfonate having 1 to 20 carbon atomsand an aryl sulfonate. The alkyl group of the alkyl sulfonate may have asubstituent, and examples of the substituent include fluorine, chlorine,bromine, an alkoxy group, an acyl group, and an aryl group. Specificexamples of the alkyl sulfonate include methane sulfonate, ethanesulfonate, butane sulfonate, hexane sulfonate, octane sulfonate, benzylsulfonate, trifluoromethane sulfonate, pentafluoroethane sulfonate, andnonafluorobutane sulfonate. Examples of the aryl group of the arylsulfonate include a benzene ring, a naphthalene ring, and an anthracenering. The benzene ring, the naphthalene ring, and the anthracene ringmay have a substituent. As the substituent, a linear or branched alkylgroup having 1 to 6 carbon atoms or a cycloalkyl group having 3 to 6carbon atoms is preferable. Specific examples of the linear or branchedalkyl group and the cycloalkyl group include methyl, ethyl, n-propyl,isopropyl, n-butyl, i-butyl, t-butyl, n-hexyl, and cyclohexyl. Otherexamples of the substituent include an alkoxy group having 1 to 6 carbonatoms, a halogen atom, cyano, nitro, an acyl group, and an acyloxygroup.

The amine compound having a phenoxy group or the ammonium salt compoundhaving a phenoxy group denotes an amine compound or an ammonium saltcompound having a phenoxy group at a terminal of an alkyl group oppositeto a nitrogen atom. The phenoxy group may have a substituent. Examplesof the substituent of the phenoxy group include an alkyl group, analkoxy group, a halogen atom, a cyano group, a nitro group, a carboxylgroup, a carboxylate group, a sulfonate group, an aryl group, an aralkylgroup, an acyloxy group, and an aryloxy group. The substitution positionof the substituent may be any one of the 2- to 6-position. The number ofsubstituents is 1 to 5.

It is preferable that at least one oxyalkylene group is present betweena phenoxy group and a nitrogen atom. The number of oxyalkylene groups is1 or more, preferably 3 to 9, and still more preferably 4 to 6 in amolecule. Among the oxyalkylene groups, an oxyethylene group (—CH₂CH₂O—)or an oxypropylene group (—CH(CH₃)CH₂O- or —CH₂CH₂CH₂O—) is preferable,and an oxyethylene group is more preferable.

The amine compound having a phenoxy group can be obtained by heating aprimary or secondary amine having a phenoxy group and haloalkyl ether toreact with each other, adding an aqueous solution of a strong base suchas sodium hydroxide, potassium hydroxide, or tetraalkylammonium to theobtained reaction product, and performing extraction with an organicsolvent such as ethyl acetate or chloroform. Alternatively, the aminecompound having a phenoxy group can be obtained by heating a primary orsecondary amine and haloalkyl ether having a phenoxy group at a terminalto react with each other, adding an aqueous solution of a strong basesuch as sodium hydroxide, potassium hydroxide, or tetraalkylammonium tothe obtained reaction product, and performing extraction with an organicsolvent such as ethyl acetate or chloroform.

(Compound (PA) having Proton-accepting Functional Group which isdecomposed to generate Compound in which Proton Accepting Propertiesdeteriorate, disappear, or change to Acidic Properties when irradiatedwith Actinic Ray or Radiation)

The composition according to the present invention may further include,as a basic compound, a compound [hereinafter, also referred to as“compound (PA)”] having a proton-accepting functional group which isdecomposed to generate a compound in which proton accepting propertiesdeteriorate, disappear, or change to acidic properties when irradiatedwith an actinic ray or radiation.

The proton-accepting functional group denotes a functional group havinga group or an electron which can electrostatically interact with aproton, for example, a functional group which has a macrocyclicstructure such as cyclic polyether or a functional group which has anitrogen atom having an unshared electron pair not contributing toπ-conjugation. Examples of the nitrogen atom having an unshared electronpair not contributing to π-conjugation include a nitrogen atom having apartial structure represented by the following formula.

wherein “{umlaut over ( )}” represents an unshared electron pair.

Preferable examples of a partial structure of the proton-acceptingfunctional group include crown ether, azacrown ether, primary totertiary amine, pyridine, imidazole, and a pyrazine structure.

The compound (PA) is decomposed to generate a compound in which protonaccepting properties deteriorate, disappear, or change to acidicproperties when irradiated with an actinic ray or radiation. Here,proton accepting properties deteriorating, disappearing, or changing toacidic properties represents a change in proton accepting propertiescaused by adding a proton to the proton-accepting functional group, andspecifically represents that, when a proton adduct is generated usingthe compound (PA) having a proton-accepting functional group and aproton, an equilibrium constant in the equilibrium constant is reduced.

Specific examples of the compound (PA) include the following compounds.Further, specific examples of the compound (PA) include compoundsdescribed in paragraphs “0421” to “0428” of JP2014-41328A and paragraphs“0108” to “0116” of JP2014-134686A, the content of which is incorporatedherein by reference.

Among the basic compounds, one kind may be used alone, or two or morekinds may be used in combination.

The amount of the basic compound used is typically 0.001 to 10 mass %and preferably 0.01 to 5 mass % with respect to the solid content of theactinic ray-sensitive or radiation-sensitive composition.

It is preferable that a ratio (molar ratio; photoacid generator/basiccompound) of the photoacid generator used to the basic compound used inthe composition is 2.5 to 300. That is, the molar ratio is preferably2.5 or higher from the viewpoints of sensitivity and resolution, and ispreferably 300 or lower from the viewpoint of suppressing deteriorationin resolution caused by thickening of a resist pattern with the lapse oftime until a heating treatment after exposure. The molar ratio(photoacid generator/basic compound) is more preferably 5.0 to 200 andstill more preferably 7.0 to 150.

As the basic compound, for example, a compound (for example, an aminecompound, an amido group-containing compound, a urea compound, or anitrogen-containing heterocyclic compound) described in paragraphs“0140” to “0144” of JP2013-11833A can be used.

(A′) Hydrophobic Resin

The actinic ray-sensitive or radiation-sensitive resin composition mayinclude a hydrophobic resin (A′) in addition to the resin (A).

It is preferable that the hydrophobic resin is designed to be localizedon a surface of a resist film. Unlike the surfactant, the hydrophobicresin does not necessarily have a hydrophilic group in a molecule anddoes not necessarily contribute to uniform mixing with a polar/non-polarmaterial.

Examples of an effect obtained by the addition of the hydrophobic resininclude an effect of suppressing a static/dynamic contact angle of aresist film surface with respect to water and an effect of suppressingout gas.

From the viewpoint of localization on the film surface layer, thehydrophobic resin includes preferably one or more kinds and morepreferably two or more kinds among “a fluorine atom”, “a silicon atom”,and “a CH₃ partial structure included in a side chain of the resin”. Inaddition, it is preferable that the hydrophobic resin includes ahydrocarbon group having 5 or more carbon atoms. These groups may bepresent at a main chain of the resin or may be substituted with a sidechain.

In a case where the hydrophobic resin includes a fluorine atom and/or asilicon atom, the fluorine atom and/or the silicon atom in thehydrophobic resin may be present at a main chain or a side chain of theresin.

In a case where the hydrophobic resin includes a fluorine atom, it ispreferable that a partial structure having a fluorine atom is a resinthat has an alkyl group having a fluorine atom, a cycloalkyl grouphaving a fluorine atom, or an aryl group having a fluorine atom.

The alkyl group having a fluorine atom (preferably having 1 to 10 carbonatoms and more preferably having 1 to 4 carbon atoms) is a linear orbranched alkyl group in which at least one hydrogen atom is substitutedwith a fluorine atom and may further have a substituent other than afluorine atom.

The cycloalkyl group having a fluorine atom is a monocyclic orpolycyclic cycloalkyl group in which at least one hydrogen atom issubstituted with a fluorine atom and may further have a substituentother than a fluorine atom.

Examples of the aryl group having a fluorine atom include an aryl group,such as a phenyl group or a naphthyl group, in which at least onehydrogen atom is substituted with a fluorine atom. The aryl group havinga fluorine atom may further have a substituent other than a fluorineatom.

Examples of a repeating unit having a fluorine atom or a silicon atominclude a repeating unit described in paragraph “0519” ofUS2012/0251948A1.

In addition, as described above, it is preferable that the hydrophobicresin includes a CH₃ partial structure at a side chain.

Here, examples of the CH₃ partial structure included at a side chain ofthe hydrophobic resin include a CH₃ partial structure such as an ethylgroup or a propyl group.

On the other hand, a methyl group (for example, an α-methyl group of arepeating unit having a methacrylic acid structure) which is directlybonded to a main chain of the hydrophobic resin has little contributionto the surface localization of the hydrophobic resin caused by theeffect of the main chain, and thus is not included in examples of theCH₃ partial structure according to the present invention.

The details of the hydrophobic resin can be found in paragraphs “0348”to “0415” of JP2014-010245A, the content of which is incorporated hereinby reference.

As the hydrophobic resin, resins described in JP2011-248019A,JP2010-175859A, and JP2012-032544A can also be preferably used.

(E) Surfactant

The actinic ray-sensitive or radiation-sensitive resin composition mayfurther include a surfactant (E). By the actinic ray-sensitive orradiation-sensitive composition including the surfactant, particularlyin a case where an exposure light source having a wavelength of 250 nmor shorter, in particular, 220 nm or shorter is used, a pattern havingadhesiveness and reduced development defects can be formed with highsensitivity and resolution.

As the surfactant, a fluorine surfactant and/or a silicon surfactant ispreferably used.

Examples of the fluorine surfactant and/or the silicon surfactantinclude surfactants described in paragraph “0276” of US2008/0248425A. Inaddition, F-TOP EF301 or EF303 (manufactured by Shin-akita Chemical Co.,Ltd.); FLUORAD FC430, 431 or 4430 (manufactured by Sumitomo 3M Ltd.);MEGAFACE F171, F173, F176, F189, F113, F110, F177, F120, or R08(manufactured by DIC Corporation); SURFLON S-382, SC101, 102, 103, 104,105, or 106 (manufactured by Asahi Glass Co., Ltd.); TROYSOL S-366(manufactured by Troy Corporation); GF-300 or GF-150 (manufactured byToagosei Co., Ltd.); SURFLON S-393 (manufactured by AGC Seimi ChemicalCo., Ltd.); F-TOP EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351,EF352, EF801, EF802, or EF601 (manufactured by Gemco Inc.): PF636,PF656, PF6320, or PF6520 (manufactured by OMNOVA Corp.); or FTX-204G,208G, 218G, 230G, 204D, 208D, 212D, 218D, or 222D (manufactured by NeosCo., Ltd.) may be used.

A polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co.,Ltd.) can also be used as the silicon surfactant.

In addition, in addition to the above-described surfactants, asurfactant may be synthesized using a fluoro aliphatic compoundmanufactured using a telomerization method (also referred to as atelomer method) or an oligomerization method (also referred to as anoligomer method). Specifically, a polymer including a fluoro aliphaticgroup derived from fluoro aliphatic compound may be used as thesurfactant. This fluoro aliphatic compound can be synthesized, forexample, using a method described in JP2002-90991A.

In addition, a surfactant other than a fluorine surfactant and/or asilicon surfactant which is described in paragraph “0280” ofUS2008/0248425A may be used.

Among these surfactants, one kind may be used alone, or two or morekinds may be used in combination.

In a case where the actinic ray-sensitive or radiation-sensitive resincomposition includes the surfactant, the content of the surfactant ispreferably 0 to 2 mass %, more preferably 0.0001 to 2 mass %, and stillmore preferably 0.0005 to 1 mass % with respect to the total solidcontent of the composition.

(F) Other Additives

The actinic ray-sensitive or radiation-sensitive resin composition mayfurther include a dissolution inhibiting compound, a dye, a plasticizer,a photosensitizer, a light absorber, and/or a compound for promotingsolubility in the developer (for example, a phenol compound having amolecular weight of 1000 or lower, or an aliphatic or alicyclic compoundhaving a carboxy group).

The actinic ray-sensitive or radiation-sensitive resin composition mayfurther include a dissolution inhibiting compound.

Here, “dissolution inhibiting compound” denotes a compound having amolecular weight of 3000 or lower which is decomposed by the action ofan acid such that the solubility in the organic developer decreases.

[Upper Layer Film (Top Coat Film)] In the pattern forming methodaccording to the present invention, an upper layer film (top coat film)may be formed over the resist film.

It is preferable that the upper layer film is not mixed with the resistfilm and is uniformly formed above the resist film.

The upper layer film is not particularly limited, and well-known upperlayer film of the related art can be formed using a well-known method ofthe related art. For example, the upper layer film can be formed basedon the description of paragraphs “0072” to “0082” of JP2014-059543A. Asa material forming the upper layer film, for example, a polymerdescribed in paragraph “0072” of JP2014-059543A or a hydrophobic resincan be used. As the hydrophobic resin, for example, the above-describedhydrophobic resin (A′) can be used.

In a case where the developer including the organic solvent is used inthe development step, it is preferable that, for example, an upper layerfilm including a basic compound described in JP2013-61648A is formed onthe resist film. Specific examples of the basic compound which may beincluded in the upper layer film include a basic compound (E) describedbelow.

In addition, it is preferable that the upper layer film includes acompound which includes at least one group or one bond selected from thegroup consisting of an ether bond, a thioether bond, a hydroxyl group, athiol group, a carbonyl bond, and an ester bond.

Further, the upper layer film may include a photoacid generator. As thephotoacid generator, the same photoacid generator (for example, theabove-described photoacid generator (B)) which may be included in theactinic ray-sensitive or radiation-sensitive composition can be used.

Hereinafter, a preferable resin which can be used in the upper layerfilm (top coat film) will be described.

(Resin)

It is preferable that the upper layer film-forming composition includesa resin. The resin which may be included in the upper layer film-formingcomposition is not particularly limited, and the same resin as thehydrophobic resin which may be included in the actinic ray-sensitive orradiation-sensitive composition (for example, the above-describedhydrophobic resin (A′)) can be used.

The details of the hydrophobic resin can be found in paragraphs “0017”to “0023” of JP2013-61647A (corresponding to paragraphs “0017” to “0023”of US2013/244438A) and in paragraphs “0016” to “0165” of JP2014-56194A,the content of which is incorporated herein by reference.

In the present invention, it is preferable that the upper layerfilm-forming composition includes a resin that includes a repeating unithaving an aromatic ring. By the upper layer film-forming compositionincluding the repeating unit having an aromatic ring, in particular,during exposure of an electron beam or an EUV ray, the generationefficiency of secondary electrons and the generation of efficiency of anacid from the compound which generates an acid by actinic ray orradiation are improved, and an effect of improving sensitivity andresolution during the formation of a pattern can be expected.

The weight-average molecular weight of the resin is preferably 3000 to100000, more preferably 3000 to 30000, and most preferably 5000 to20000. The mixing amount of the resin in the upper layer film-formingcomposition is preferably 50 to 99.9 mass %, more preferably 60 to 99.0mass %, still more preferably 70 to 99.7 mass %, and even still morepreferably 80 to 99.5 mass % with respect to the total solid content.

In a case where the upper layer film-forming composition (top coatcomposition) includes a plurality of resins, it is preferable that upperlayer film-forming composition includes at least one resin (XA) having afluorine atom and/or a silicon atom.

Regarding a preferable range of the content of the fluorine atom and thesilicon atom included in the resin (XA), the content of a repeating unithaving a fluorine atom and/or a silicon atom in the resin (XA) ispreferably 10 to 100 mass %, preferably 10 to 99 mol %, and morepreferably 20 to 80 mol %.

In addition, it is more preferable that the upper layer film-formingcomposition includes at least one resin (XA) having a fluorine atomand/or a silicon atom and a resin (XB) in which the content of afluorine atom and/or a silicon atom is lower than that of the resin(XA). As a result, during the formation of the upper layer film, theresin (XA) is eccentrically present on the surface of the upper layerfilm. Therefore, the performance such as developing characteristics orfollowability of immersion liquid can be improved.

The content of the resin (XA) is preferably 0.01 to 30 mass %, morepreferably 0.1 to 10 mass %, still more preferably 0.1 to 8 mass %, andeven still more preferably 0.1 to 5 mass % with respect to the totalsolid content of the upper layer film-forming composition. The contentof the resin (XB) is preferably 50.0 to 99.9 mass %, more preferably 60to 99.9 mass %, still more preferably 70 to 99.9 mass %, and even stillmore preferably 80 to 99.9 mass % with respect to the total solidcontent of the upper layer film-forming composition.

It is preferable that the resin (XB) does not substantially include afluorine atom and a silicon atom. In this case, specifically, the totalcontent of a repeating unit having a fluorine atom and a repeating unithaving a silicon atom is preferably 0 to 20 mol %, more preferably 0 to10 mol %, still more preferably 0 to 5 mol %, even still more preferably0 to 3 mol %, and ideally 0 mol % (that is, a fluorine atom and asilicon atom are not included) with respect to all the repeating unitsof the resin (XB).

<Method of Preparing Upper Layer Film-Forming Composition (Top CoatComposition)>

It is preferable that the respective components of the upper layerfilm-forming composition are dissolved in a solvent and are filteredthrough a filter. As the filter, a filter formed ofpolytetrafluoroethylene, polyethylene, or nylon and having a pore sizeof preferably 0.1 μm or less, more preferably 0.05 μm or less, and stillmore preferably 0.03 μm or less is preferable. A plurality of filtersmay be connected in series or in parallel. In addition, the compositionmay be filtered multiple times, and a step of filtering variousmaterials multiple times may be a cycle filtration step. Further, beforeand after the filter filtration, degassing or the like may be performedon the composition. It is preferable that the upper layer film-formingcomposition does not include impurities such as metal. The content ofthe metal components in the materials is preferably 10 ppm or lower,more preferably 5 ppm or lower, and still more preferably 1 ppm orlower, and it is still most preferable that the materials do notsubstantially include the metal components (the measured value is lowerthan a detection limit value of a measuring device).

In a case where immersion exposure is performed in the <exposure step>,the upper layer film is disposed between the actinic ray-sensitive orradiation-sensitive film and functions as a layer that prevents directcontact between the actinic ray-sensitive or radiation-sensitive filmand the immersion liquid. In this case, preferable characteristics ofthe upper layer film (upper layer film-forming composition) includesuitability for application to the actinic ray-sensitive orradiation-sensitive film, transparency to radiation, particularly, lightat 193 nm, and insolubility in the immersion liquid (preferably water).In addition, it is preferable that the upper layer film is uniformlyapplied to the surface of the actinic ray-sensitive orradiation-sensitive film without being mixed with the actinicray-sensitive or radiation-sensitive film.

In order to uniformly apply the upper layer film-forming composition tothe surface of the actinic ray-sensitive or radiation-sensitive filmwithout dissolving the actinic ray-sensitive or radiation-sensitivefilm, it is preferable that the upper layer film-forming compositionincludes a solvent in which the actinic ray-sensitive orradiation-sensitive film is not soluble. As the solvent in which theactinic ray-sensitive or radiation-sensitive film is not soluble, it ismore preferable that a solvent having different components from those ofa developer (organic developer) including an organic solvent is used.

An application method of the upper layer film-forming composition is notparticularly limited, and a spin coating method, a spray coating method,a roller coating method, or a dipping method that is well-known in therelated art can be used.

The thickness of the upper layer film is not particularly limited, andfrom the viewpoint of transparency to an exposure light source, istypically 5 nm to 300 nm, preferably 10 nm to 300 nm, more preferably 20nm to 200 nm, and still more preferably 30 nm to 100 nm.

After the formation of the upper layer film, the substrate is optionallyheated (PB).

From the viewpoint of resolution, it is preferable that the refractiveindex of the upper layer film is close to the refractive index of theactinic ray-sensitive or radiation-sensitive film.

It is preferable that the upper layer film is insoluble in the immersionliquid, and it is more preferable that the upper layer film is insolublein water.

From the viewpoint of followability of immersion liquid, the recedingcontact angle (23° C.) of the immersion liquid on the upper layer filmis preferably 50 to 100 degrees and more preferably 80 to 100 degrees.

During the immersion exposure, it is necessary that the immersion liquidmoves on a wafer following a movement of an exposure head that scans thewafer with high speed to form an exposure pattern. Therefore, thecontact angle of the immersion liquid on the actinic ray-sensitive orradiation-sensitive film in a dynamic state is important, and it ispreferable that the receding contact angle is in the above-describedrange in order to obtain higher resist performance.

In a case where the upper layer film is peeled, an organic developer maybe used, or a peeling liquid may be separately used. As the peelingliquid, a solvent having low permeability to the actinic ray-sensitiveor radiation-sensitive film is preferable. From the viewpoint that thepeeling of the upper layer film and the development of the actinicray-sensitive or radiation-sensitive film can be performed at the sametime, it is preferable that the upper layer film can be peeled off usingthe organic developer. The organic developer used for peeling is notparticularly limited as long as it can dissolve and remove a lowexposure portion of the actinic ray-sensitive or radiation-sensitivefilm.

From the viewpoint of peeling the upper layer film using the organicdeveloper, the dissolution rate of the upper layer film in the organicdeveloper is preferably 1 to 300 nm/sec and more preferably 10 to 100nm/sec.

Here, the dissolution rate of the upper layer film in the organicdeveloper is a rate at which the film thickness is reduced when theupper layer film is formed and then is exposed to the developer. In thepresent invention, the dissolution rate is a rate when the upper layerfilm is dipped in butyl acetate at 23° C.

By adjusting the dissolution rate of the upper layer film in the organicdeveloper to be 1 nm/sec or higher and preferably 10 nm/sec or higher,an effect of reducing the occurrence of development defects afterdeveloping the actinic ray-sensitive or radiation-sensitive film can beobtained. In addition, by adjusting the dissolution rate of the upperlayer film in the organic developer to be 300 nm/sec or lower andpreferably 100 nm/sec or lower, an effect of further improving the lineedge roughness of a pattern after developing the actinic ray-sensitiveor radiation-sensitive film can be obtained due to the effect of reduceduneven exposure during immersion exposure.

The upper layer film may be removed using another well-known developer,for example, an alkali aqueous solution. Specific examples of the alkaliaqueous solution that can be used include an aqueous solution oftetramethylammonium hydroxide.

<Method of Manufacturing Semiconductor Device>

The present invention relates to a method of manufacturing an electronicdevice. In a pattern forming step of the method of manufacturing asemiconductor device according to the present invention, the treatmentliquid according to the present invention may be used as any one of adeveloper, a rinsing liquid, and a pre-wet liquid as described above, ormay be used as, for example, a peeling liquid for peeling a pattern asdescribed below.

In a general method of manufacturing a semiconductor element, first, agate insulating film formed of a high dielectric constant material (forexample, HfSiO₄, ZiO₂, ZiSiO₄, Al₂O₃, HfO₂, or La₂O₃) or the like or agate electrode layer formed of polysilicon or the like is formed on asilicon substrate (for example, an ion-implanted n-type or p-typesilicon substrate) using a technique such as sputtering (etched layerforming step). Next, an actinic ray-sensitive or radiation-sensitiveresin composition is applied to the formed gate insulating film or theformed gate electrode layer. A pattern is formed using theabove-described pattern forming method, and a non-masked region isdry-etched or wet-etched by using this pattern as a mask (etching step).As a result, the gate insulating film, the gate electrode layer, or thelike is removed. Next, in an ion implantation treatment (ionimplantation step), an ionized p-type or n-type impurity element isimplanted into the silicon substrate to form a p-type or n-type impurityimplanted region (so-called a source/drain region). Next, optionally,after performing an ashing treatment (ashing step), a treatment ofpeeling the resist film remaining on the substrate is performed.

<Peeling Step>

In the method of manufacturing a semiconductor device according to thepresent invention, a peeling treatment is not particularly limited, asheet type or a batch type can be performed. A sheet type is a method oftreating wafers one by one. One embodiment of the sheet type is a methodof spreading the treatment liquid all over the surface of the waferusing a spin coater and treating the wafer. The liquid temperature of aremover, the discharge amount of the remover, and the rotation speed ofthe wafer using the spin coater are selected as appropriate valuesaccording to the selection of a substrate as a target. In theembodiment, conditions for performing a resist peeling step are notparticularly limited, and the sheet type peeling step is preferable. Inthe sheet type peeling step, a semiconductor substrate is transported orrotated in a predetermined direction, and a remover is brought intocontact with the semiconductor substrate in this space by discharging,jetting, flowing, dropwise addition, or the like. Optionally, theremover may be sprayed while rotating the semiconductor substrate usinga spin coater. On the other hand, in the batch type peeling step, asemiconductor substrate is dipped in a liquid bath containing a removersuch that the semiconductor substrate and the remover come into contactwith each other in the liquid bath. These peeling types may beselectively used depending on a structure or a material of an element.The temperature at which peeling is performed is not particularlylimited and is preferably 35° C. or lower and more preferably 30° C. orlower. As long as the treatment liquid according to the presentinvention is present as a liquid at a relatively low temperature, thelower limit value of the temperature at which peeling is performed isnot particularly limited, and is preferably 15° C. or higher from theviewpoint of throughput or the like during manufacturing. In the case ofthe sheet type treatment, the supply rate of the remover is notparticularly limited and varies depending on the size of the substrate.For example, the supply rate is preferably 0.3 to 3 L/min and morepreferably 0.5 to 2 L/min. By adjusting the supply rate to he theabove-described lower limit value or higher, the in-plane uniformity canbe secured, which is preferable. By adjusting the supply rate to be theabove-described upper limit value or higher, stable performance can besecured during a continuous treatment, which is preferable. When thesubstrate is rotated, the rotation speed varies depending on the size ofthe substrate and, from the same viewpoint, is preferably 100 to 1000rpm. “Temperature” described here refers to the surface temperature of asubstrate to be treated in the case of the sheet type treatment, andrefers to the liquid temperature of the remover in the case of the batchtype treatment.

An electronic device that is manufactured using the method ofmanufacturing a semiconductor device according to the present inventioncan be suitably mounted on electric and electronic apparatuses (homeelectronics, apparatuses relating to office automation (OA) and media,optical apparatuses, and communication apparatuses).

EXAMPLES

Hereinafter, the present invention will be described in detail usingExamples, but the scope of the present invention is not limited thereto.

In the following examples, all the preparation, storage, filling,analysis, and measurement of the treatment liquids were performed in aclean room satisfying a level of ISO Class 2 or lower.

Examples 1 to 48 and Comparative Examples 1 to 17

<Preparation and Storage of Treatment Liquid for ManufacturingSemiconductor>

Each of butyl acetate (nBA), N-methyl-2-pyrrolidone (NMP), isopropanol(IPA), ethanol, methyl isobutyl carbinol (MIBC), propylene glycolmonomethyl ether (PGME), cyclohexanone (CyHx), γ-butyrolactone (GBL),ethyl lactate (EL), dimethyl sulfoxide (DMSO), isoamyl acetate (iAA), amixed solution (PGMEA/PGME=7/3 (volume ratio)) of propylene glycolmonomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether(PGME), methyl 2-hydroxyisobutyrate (HBM), methyl ethyl ketone (MEK),and propylene carbonate (PC) was repeatedly purified using adistillation column having an inner wall formed of glass until thecontent of each of Fe, Cu, and Zn as the target metals was lower than 10mass ppt with respect to the total mass of each of treatment liquids. Asa result, each of the treatment liquids was obtained. In addition, a2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution wasrepeatedly purified using a well-known method. As a result, treatmentliquids in which the content of each of Fe, Cu, and Zn as the targetmetals was lower than 10 mass ppt with respect to the total mass of eachof treatment liquids were obtained.

Ultrapure water used in Examples was purified using a method describedin JP2007-254168A and was used for adjusting the treatment liquid afterverifying that the content of each of Fe, Cu, and Zn as the targetmetals was lower than 10 mass ppt with respect to the total mass of eachof the treatment liquids.

The obtained various treatment liquids were filled into storagecontainers shown in Table 1 and were stored at 25° C. for 30 days. As aresult, the various treatment liquids shown in Table 1: A1 to A26 (butylacetate: nBA), A101 to A117 (butyl acetate), B (N-methyl-2-pyrrolidone:NMP), C1 and C2 (isopropanol: IPA), D (ethanol), E1 and E2 (methylisobutyl carbinol: MIBC), F1 to F4 (2.38 mass % TMAH aqueous solution),G (PGME), H (cyclohexanone: CyHx), I (γ-butyrolactone: GBL), J (ethyllactate: EL), K (dimethyl sulfoxide: DMSO), L (isoamyl acetate: iAA), M1and M2 (PGMEA/PGME (volume ratio=7/3)), N (methyl 2-hydroxyisobutyrate:HBM), O (methyl ethyl ketone: MEK), and P (propylene carbonate: PC) wereobtained.

<Storage Container>

As the storage container, each of the storage containers shown in Table1 was used after cleaning the inner wall of the storage portion usingeach of cleaning liquids shown in Table 1.

[Storage Container]

The storage containers shown in Table 1 are as follows.

PE: storage container in which an inner wall of a storage portion wasformed of polyethylene (PE)

PP: storage container in which an inner wall of a storage portion wasformed of polypropylene (PP)

PTFE: storage container in which an inner wall of a storage portion wasformed of polytetrafluoroethylene (PTFE)

PTFE Coating: storage container in which an inner wall of a storageportion was coated with PTFE

PFA: storage container in which an inner wall of a storage portion wasformed of perfluoroalkoxy alkane (PFA)

Electropolished Stainless Steel: storage container in which an innerwall of a storage portion was formed of electropolished stainless steel(SUS316L)

Buffed Stainless Steel: storage container in which an inner wall of astorage portion was formed of buffed stainless steel (SUS316L)

Electropolished HASTELLOY: storage container in which an inner wall of astorage portion was formed of electropolished HASTELLOY

Electropolished INCONEL: storage container in which an inner wall of astorage portion was formed of electropolished INCONEL

Electropolished MONEL: storage container in which an inner wall of astorage portion was formed of electropolished MONEL

[Cleaning Liquid]

The cleaning liquids shown in Table 1 are as follows.

IPA: isopropyl alcohol (manufactured by Kanto Chemical Co., Inc./Grade:semiconductor grade)

DIW: ultrapure water (the LPC value* of particles having a diameter of40 nm or more was 10 particles/mL or less)

Method of Measuring *LPC (Liquid Particle Counter) Value

The LPC value of DIW (ultrapure water) was obtained by counting thenumber of particles having a diameter of 40 nm or more in 10 mL of aliquid sample using a liquid particle counter (KS-18FX; manufactured byRion Co., Ltd.) and calculating the number of particles in the liquidsample per 1 mL.

Cleaning liquid A: cleaning liquid obtained by diluting a cleaningliquid for a semiconductor (Pure Soft PS, manufactured by AS ONECorporation) to 100 times with ultrapure water

[Contact Angle]

The contact angle of the cleaning liquid on the inner wall of thestorage portion of the storage container was measured using thefollowing method.

Device: DM-701 (manufactured by Kyowa Interface Science Co., Ltd.)

Measurement method: θ/2 method

A target liquid was dropped on a specimen having a size of 3 cm×3 cm andformed of the same material as the inner wall of the storage portion,and a contact angle θ was calculated from the shape of formed liquiddroplet according to the θ/2 method.

The contact angle θ was obtained by obtaining the radius r and height hof the cleaning liquid 11 (liquid droplet) shown in FIG. 1 andsubstituting the obtained the radius r and height h into the followingexpression. In FIG. 1 , reference numeral 12 represents the apex of theliquid droplet.tan θ₁ =h/r→θ=2 arctan(h/r)

[Cleaning Method]

An opening of the storage portion of the storage container faceddownward, each of the various cleaning liquids was jetted from theopening using a shower nozzle at a flow rate of 2 L/min for 1 minute toclean the storage container. Next, the container was sufficiently rinsedwith ultrapure water and then was dried.

[Measurement of Ratio Cr/Fe]

The film formed of each of the materials used for the inner walls of thestorage containers and having a well-known film thickness was etched. Anetching rate of each of the materials was calculated based on the timeat which the etching ended and the film thickness. Based on this etchingrate, each of the inner wall materials was etched from the surface to adepth of 1 nm.

As detected elements during the etching, the concentrations of C, N, O,Cr, Fe, Ni, Mn, and S were evaluated. A ratio Cr/Fe was calculated basedon the obtained concentrations (wt %). In addition, etching ESCA wasperformed using Quantera (manufactured by ULVAC-PHI, Inc.).

<Evaluation>

Regarding each of the treatment liquids A1 to A26 (butyl acetate), A101to A117 (butyl acetate), B (NMP), C1 and C2 (IPA), D (ethanol), E1 andE2 (MIBC), F1 to F4 (2.38 mass % TMAH aqueous solution), G (PGME), H(CyHx), I (GBL), J (EL), K (DMSO), L (iAA), M1 and M2 (PGMEA/PGME(volume ratio=7/3)), N (HBM), O (MEK), and P (PC) shown in Table 1, thetotal metal amount and the content of particulate metal were measuredusing the following methods. In Table 1, “mass ppt” is a value withrespect to the total mass of the treatment liquid.

In addition, regarding each of the treatment liquids A1 to A24, A101 toA117, B, C1 and C2, D, E, and F1 to F4, the defect performance wasevaluated using the following method.

[Measurement of Total Metal Content and Particulate Metal Content(SP-ICP-MS Method)]

1) Preparation of Standard Material

Ultrapure water was weighed and charged into a clean glass container,and measurement target metal particles having a median size of 50 nmwere added thereto such that the concentration was 10000 atoms/ml. Next,the solution was treated using an ultrasonic cleaning machine for 30minutes to obtain a dispersion. This dispersion was used as a standardmaterial for transport efficiency measurement.

2) SP-ICP-MS Device Used

Manufacturer: PerkinElmer

Model: NexION 350S

3) Measurement Conditions of SP-ICP-MS

In SP-ICP-MS, the measurement target liquid was aspirated at about 0.2mL/min using a PFA coaxial nebulizer formed of PFA, a cyclonic spraychamber formed of quartz, and a torch injector having an inner diameterof 1 mm formed of quartz. The addition amount of oxygen was set as 0.1L/min, the plasma power was set as 1600 W, and the inside of the cellwas purged using ammonia gas. The temporal resolution was set as 50 μsfor analysis.

The amount of ionic metal, the amount of particulate metal, and thetotal metal amount that is the sum of the amount of ionic metal and theamount of particulate metal were measured using the following analysissoftware manufactured by the manufacturers.

The amount of ionic metal and the amount of particulate metal:SyngistixNano Application Module for “SP-ICP-MS”, nanoparticle analysis:Totalmetal amount:Syngistix for ICP-MS Software

[Measurement of Number of Defects]

Using a wafer surface inspection device (SP-5, manufactured byKLA-Tencor Corporation), the number of particles having a diameter of 32nm or more present on a silicon substrate surface having a diameter of300 mm was calculated. Next, this silicon substrate was set on a spindischarge device, and the prepared various treatment liquids weredischarged to the surface of the silicon substrate at a flow rate of 1.5L/min while rotating the silicon substrate. Next, the silicon wafer wasrinsed and dried. Regarding the obtained sample, the number of particlespresent on the silicon substrate surface was measured again using thedevice (SP-5), and increased particles were selected. Regarding theselected particles, elemental analysis was performed using a defectreview device (SEM Vision G6; manufactured by Applied Materials Inc.),and particles in which the target metals were detected were set as“defects”. The obtained number of defects was evaluated based on thefollowing standards. The results are shown in Table 1. In the followingstandards, the evaluation C represents that the performance ofsuppressing defects that is required for the treatment liquid formanufacturing a semiconductor is achieved.

A: the number of defects was 0 to 50

B: the number of defects was more than 50 and 100 or less

C: the number of defects was more than 100 and 500 or less

D: the number of defects was more than 500 and 1000 or less

E: the number of defects was more than 1000

TABLE 1 Total Amount of Defect Cleaning Contact Angle Particulate MetalSuppressing Treatment Liquid Storage Container Cr/Fe Liquid Degree massppt Performance Example 1 A1 nBA Electropolished Stainless Steel 2 DIW95 0.15 A Example 2 A2 nBA Electropolished Stainless Steel 2 DIW 95 5 AExample 3 A3 nBA Electropolished Stainless Steel 2 DIW 95 21 B Example 4A4 nBA Electropolished Stainless Steel 2 DIW 95 22 B Example 5 A5 nBAElectropolished Stainless Steel 2 DIW 95 9 A Example 6 A6 nBAElectropolished Stainless Steel 2 DIW 95 17 B Example 7 A7 nBAElectropolished Stainless Steel 2 DIW 95 17 B Example 8 A8 nBAElectropolished Stainless Steel 2 DIW 95 17 B Example 9 A9 nBAElectropolished Stainless Steel 2 DIW 95 45 B Example 10 A10 nBAElectropolished Stainless Steel 2 DIW 95 7 A Example 11 A11 nBAElectropolished Stainless Steel 2 DIW 95 52 C Example 12 A12 nBAElectropolished Stainless Steel 2 DIW 95 82 C Example 13 A13 nBAElectropolished Stainless Steel 2 DIW 95 9 A Example 14 A14 nBAElectropolished Stainless Steel 2 DIW 95 45 B Example 15 A15 nBAElectropolished Stainless Steel 2 DIW 95 9 A Example 16 A16 nBAElectropolished Stainless Steel 2 DIW 95 45 B Example 17 B NMPElectropolished Stainless Steel 2 DIW 95 4 A Example 18 C1 IPAElectropolished Stainless Steel 2 DIW 95 1 A Example 19 C2 IPAElectropolished Stainless Steel 2 IPA 25 1.22 A Example 20 D EthanolElectropolished Stainless Steel 2 DIW 95 5 A Example 21 E1 MIBCElectropolished Stainless Steel 2 DIW 95 1 A Example 22 F1 TMAH PE DIW90 0.19 A Example 23 F2 TMAH PP DIW 95 0.43 A Example 24 F3 TMAH PTFEDIW 108 0.06 A Example 25 F4 TMAH PFA DIW 75 0.04 A Example 26 A17 nBAElectropolished Stainless Steel 2 DIW 95 1.2 A Example 27 A18 nBAElectropolished Stainless Steel 2 DIW 95 1.12 A Example 28 A19 nBAElectropolished INCONEL 2 DIW 85 4.47 A Example 29 A20 nBAElectropolished HASTELLOY 2 DIW 85 2.77 A Example 30 A21 nBAElectropolished MONEL 2 DIW 85 9.24 A Example 31 A22 nBA ElectropolishedStainless Steel 2 IPA 25 11.8 B Example 32 A23 nBA ElectropolishedStainless Steel 2 Cleaning 9 1.4 B Liquid A Example 33 A24 nBA PTFECoating DIW 128 2 B Example 34 A25 nBA Electropolished Stainless Steel 1DIW 95 0.15 A Example 35 A26 nBA Electropolished Stainless Steel 3 DIW95 0.15 A Example 36 A1 nBA Electropolished Stainless Steel 4 DIW 950.15 B Example 37 G PGME Electropolished Stainless Steel 2 DIW 95 0.15 AExample 38 H CyHx Electropolished Stainless Steel 2 DIW 95 0.15 AExample 39 I GBL Electropolished Stainless Steel 2 DIW 95 0.15 A Example40 E2 MIBC Electropolished Stainless Steel 2 DIW 95 0.15 A Example 41 JEL Electropolished Stainless Steel 2 DIW 95 0.15 A Example 42 K DMSOElectropolished Stainless Steel 2 DIW 95 0.15 A Example 43 L iAAElectropolished Stainless Steel 2 DIW 95 0.15 A Example 44 M1 PGMEA/Electropolished Stainless Steel 2 DIW 95 0.15 A PGME Example 45 N HBMElectropolished Stainless Steel 2 DIW 95 0.15 A Example 46 O MEKElectropolished Stainless Steel 2 DIW 95 0.15 A Example 47 P PCElectropolished Stainless Steel 2 DIW 95 0.15 A Example 48 M2 GBLElectropolished Stainless Steel 2 DIW 95 0.15 A Comparative A101 nBAElectropolished Stainless Steel 2 DIW 95 130 D Example 1 ComparativeA102 nBA Electropolished Stainless Steel 2 DIW 95 130 D Example 2Comparative A103 nBA Electropolished Stainless Steel 2 DIW 95 130 DExample 3 Comparative A104 nBA Electropolished Stainless Steel 2 DIW 95360 D Example 4 Comparative A105 nBA Electropolished Stainless Steel 2DIW 95 240 D Example 5 Comparative A106 nBA Electropolished StainlessSteel 2 DIW 95 430 E Example 6 Comparative A107 nBA ElectropolishedStainless Steel 2 DIW 95 430 E Example 7 Comparative A108 nBAElectropolished Stainless Steel 2 DIW 95 430 E Example 8 ComparativeA109 nBA Electropolished Stainless Steel 2 DIW 95 126 D Example 9Comparative A110 nBA Electropolished Stainless Steel 2 DIW 95 430 EExample 10 Comparative A111 nBA Electropolished Stainless Steel 2 DIW 951,200 E Example 11 Comparative A112 nBA Electropolished Stainless Steel2 DIW 95 126 D Example 12 Comparative A113 nBA Electropolished StainlessSteel 2 DIW 95 430 E Example 13 Comparative A114 nBA ElectropolishedStainless Steel 2 DIW 95 1,200 E Example 14 Comparative A115 nBAElectropolished Stainless Steel 2 DIW 95 0.00 D Example 15 ComparativeA116 nBA Electropolished Stainless Steel 2 DIW 95 0.00 D Example 16Comparative A117 nBA Buffed Stainless Steel 0.8 DIW 78 103.4 E Example17 Fe Cu Zn Total Amount of Total Amount of Total Amount of Sum of TotalAmount Metal Particulate Metal Particulate Metal Particulate Total Metalof Particulate Amount Metal Amount Metal Amount Metal Amounts MetalTreatment Liquid mass ppt mass ppt mass ppt mass ppt mass ppt mass pptmass ppt mass ppt Example 1 A1 nBA 1 0.1 1 0.03 0.3 0.02 2.3 0.15Example 2 A2 nBA 50 3 10 1 10 1 70 5 Example 3 A3 nBA 50 10 50 9 10 2110 21 Example 4 A4 nBA 10 2 50 11 50 9 110 22 Example 5 A5 nBA 50 3 503 50 3 150 9 Example 6 A6 nBA 200 15 10 1 10 1 220 17 Example 7 A7 nBA10 1 200 15 10 1 220 17 Example 8 A8 nBA 10 1 10 1 200 15 220 17 Example9 A9 nBA 200 15 200 15 200 15 600 45 Example 10 A10 nBA 150 5 15 1 15 1180 7 Example 11 A11 nBA 500 50 15 1 15 1 530 52 Example 12 A12 nBA1,000 80 15 1 15 1 1030 82 Example 13 A13 nBA 50 3 50 3 50 3 150 9Example 14 A14 nBA 200 15 200 15 200 15 600 45 Example 15 A15 nBA 50 350 3 50 3 150 9 Example 16 A16 nBA 200 15 200 15 200 15 600 45 Example17 B NMP 22 3.1 11 1 3 0.3 36 4 Example 18 C1 IPA 12 1.3 2 0.1 0.2 0.0214.2 1 Example 19 C2 IPA 11 1.1 1 0.1 0.3 0.02 12.3 1.22 Example 20 DEthanol 31 2.3 19 2.1 2 0.1 52 5 Example 21 E1 MIBC 9 0.7 3 0.5 1 0.0813 1 Example 22 F1 TMAH 1 0.09 1 0.05 1 0.05 3 0.19 Example 23 F2 TMAH 40.3 2 0.1 1 0.03 7 0.43 Example 24 F3 TMAH 0.3 0.02 0.2 0.03 0.05 0.010.55 0.06 Example 25 F4 TMAH 0.8 0.01 0.3 0.02 0.1 0.01 1.2 0.04 Example26 A17 nBA 13 1 2 0.1 0.9 0.1 15.9 1.2 Example 27 A18 nBA 9 0.9 1.9 0.20.3 0.02 11.2 1.12 Example 28 A19 nBA 53 4.3 0.9 0.07 0.5 0.1 54.4 4.47Example 29 A20 nBA 33 2.7 0.7 0.05 0.3 0.02 34 2.77 Example 30 A21 nBA29 2.9 58 6.3 0.4 0.04 87.4 9.24 Example 31 A22 nBA 28 6.3 21 5.1 3 0.452 11.8 Example 32 A23 nBA 63 0.9 51 0.4 14 0.1 128 1.4 Example 33 A24nBA 58 0.6 42 0.5 9 0.9 109 2 Example 34 A25 nBA 1 0.1 1 0.03 0.4 0.022.4 0.15 Example 35 A26 nBA 1 0.1 2 0.03 0.3 0.02 3.3 0.15 Example 36 A1nBA 1 0.1 1 0.03 0.3 0.02 2.3 0.15 Example 37 G PGME 2 0.1 1 0.03 0.30.02 3.3 0.15 Example 38 H CyHx 1 0.1 2 0.03 0.3 0.02 3.3 0.15 Example39 I GBL 1 0.1 1 0.03 0.3 0.02 2.3 0.15 Example 40 E2 MIBC 1 0.1 1 0.030.4 0.02 2.4 0.15 Example 41 J EL 2 0.1 1 0.03 0.5 0.02 3.5 0.15 Example42 K DMSO 1 0.1 3 0.03 0.3 0.02 4.3 0.15 Example 43 L iAA 1 0.1 1 0.030.3 0.02 2.3 0.15 Example 44 M1 PGMEA/ 1 0.1 1 0.03 0.3 0.02 2.3 0.15PGME Example 45 N HBM 2 0.1 2 0.03 0.4 0.02 4.4 0.15 Example 46 O MEK 10.1 1 0.03 0.3 0.02 2.3 0.15 Example 47 P PC 2 0.1 1 0.03 0.3 0.02 3.30.15 Example 48 M2 GBL 1 0.1 1 0.03 0.3 0.02 2.3 0.15 Comparative A101nBA 2,000 120 100 5 100 5 2200 130 Example 1 Comparative A102 nBA 100 52,000 120 100 5 2200 130 Example 2 Comparative A103 nBA 100 5 100 52,000 120 2200 130 Example 3 Comparative A104 nBA 2,000 120 2,000 1202,000 120 6000 360 Example 4 Comparative A105 nBA 1,000 80 1,000 801,000 80 3000 240 Example 5 Comparative A106 nBA 10,000 400 200 15 20015 10400 430 Example 6 Comparative A107 nBA 200 15 10,000 400 200 1510400 430 Example 7 Comparative A108 nBA 200 15 200 15 10,000 400 10400430 Example 8 Comparative A109 nBA 2,000 120 50 3 50 3 2100 126 Example9 Comparative A110 nBA 10,000 400 200 15 200 15 10400 430 Example 10Comparative A111 nBA 10,000 400 10,000 400 10,000 400 30000 1,200Example 11 Comparative A112 nBA 2,000 120 50 3 50 3 2100 126 Example 12Comparative A113 nBA 10,000 400 200 15 200 15 10400 430 Example 13Comparative A114 nBA 10,000 400 10,000 400 10,000 400 30000 1,200Example 14 Comparative A115 nBA 2 0.00 2 0.00 2 0.00 6 0.00 Example 15Comparative A116 nBA 10 0.00 2 0.00 2 0.00 14 0.00 Example 16Comparative A117 nBA 723 84.5 109 18 3.5 0.9 835.5 103.4 Example 17

It was found from the results that the number of defects is notproportional to the total metal amount of Fe, Cu, and Zn in thetreatment liquid, that is, the total mass of the metal atoms. On theother hand, it was found that, in a case where the ratio of the totalmass of particulate metal derived from Fe, Cu, and Zn measured by theSP-ICP-MS method to the total mass of the treatment liquid is in therange of the present invention, the number of defects is small.

Examples 101 to 115

<Preparation and Storage of Treatment Liquid for ManufacturingSemiconductor>

As a treatment liquid for manufacturing a semiconductor, isopropanol waspurified using a well-known method. As a result, treatment liquids inwhich the content of each of Fe, Cu, and Zn as the target metals waslower than 10 mass ppt with respect to the total mass of each of thetreatment liquids were obtained.

The obtained treatment liquids were filled into storage portions ofstorage containers shown in Table 2 and were stored at 25° C. for 30days. As a result, various treatment liquids: C3 to C17 (isopropanol:IPA) shown in Table 2 were obtained.

At this time, a void portion of the storage portion was filled withfiller gas shown in Table 2.

<Storage Container>

As the storage container, each of the storage containers shown in Table2 was used after cleaning the inner wall of the storage portion usingeach of cleaning liquids shown in Table 2.

[Storage Container]

The storage containers shown in Table 2 are as follows.

PE: storage container in which an inner wall of a storage portion wasformed of polyethylene (PE)

[Cleaning Liquid]

The cleaning liquids shown in Table 2 are as follows.

DIW: ultrapure water (the LPC value* of particles having a diameter of40 nm or more was 10 particles/mL or less)

[Method of Cleaning Container]

The storage portion of the storage container storing the treatmentliquid was cleaned using the following method.

A: the cleaning liquid was put into the storage portion until 20% of thevolume of the storage portion was filled, was shaken for 1 minutes, andthen was rinsed with ultrapure water

B: A was repeated three times C: an opening of the storage portion ofthe storage container faced downward, the cleaning liquid was jettedfrom the opening using a shower nozzle at a flow rate of 2 L/min for 1minute to clean the storage container. Next, the container wassufficiently rinsed with ultrapure water and then was dried.

[Cleanliness of Filler Gas]

The cleanliness of the filler gas shown in Table 2 is based on thefollowing evaluation standards. Here, the cleanliness of the filler gaswas measured using the following method.

A: the number of particles having a diameter of 0.5 μm or more is 1particles/L or less

B: the number of particles having a diameter of 0.5 μm or more is 2particles/L to 10 particles/L

C: the number of particles having a diameter of 0.5 μm or more is morethan 10 particles/L

Device: liquid particle counter (KC-03A; manufactured by Rion Co., Ltd.)

Measurement method: a tip of a gas suction tube was fixed to ameasurement target portion, target gas was aspirated at a flow rate of 3L/min, the number of particles having a diameter of 0.5 μm or more wascounted, and the number of particles per 1 L was calculated.

[Void Volume (vol %)]

The inner volume of the storage portion was calculated based on anincreased mass amount in a case where 100% of the storage portion wasfilled with ultrapure water. In a case where the void volume was higherthan 1%, the mass of a solution to be filled was obtained based on thevolume of the solution, which is a desired void volume, and the specificgravity of the solution, and the filling amount was adjusted based onthe increased mass amount. In a case where the void volume was lowerthan 1%, the filling amount was adjusted by filling 100% of the storageportion with the solution and then aspirating the solution using a cleanspoid in an amount corresponding to the volume of the gas which is adesired void volume.

<Evaluation>

Regarding each of the treatment liquids C3 to C17 (isopropanol) shown inTable 2, the total metal amount and the particulate metal content weremeasured using a method shown in Table 1. In Table 2, “mass ppt” is avalue with respect to the total mass of the treatment liquid.

In addition, regarding each of the treatment liquids C3 to C17, thedefect performance was evaluated using a method shown in Table 1. Theresults are shown in Table 2.

TABLE 2 Total Amount of Defect Treatment Storage Cleaning CleaningFiller Void Volume Particulate Metal Suppressing Liquid Container LiquidMethod Gas Cleanliness vol % mass ppt Performance Example 101 C3 IPA PEDIW A Air A 20 10.2 B Example 102 C4 IPA PE DIW B Air A 20 1.4 A Example103 C5 IPA PE DIW C Air A 20 1.42 A Example 104 C6 IPA PE None None AirA 20 57 C Example 105 C7 IPA PE DIW C Air A 20 0.81 A Example 106 C8 IPAPE DIW C Argon A 20 0.71 A Example 107 C9 IPA PE DIW C Air B 20 16.3 BExample 108 C10 IPA PE DIW C Air C 20 98.2 C Example 109 C11 IPA PE DIWC Air B 0.00 10.2 B Example 110 C12 IPA PE DIW C Air B 0.01 5.29 AExample 111 C13 IPA PE DIW C Air B 1 0.38 A Example 112 C14 IPA PE DIW CAir B 10 0.71 A Example 113 C15 IPA PE DIW C Air B 45 11 B Example 114C16 IPA PE DIW C Air B 60 64.2 C Example 115 C17 IPA PE DIW C Air B 9088 C Fe Cu Zn Total Amount of Total Amount of Total Amount of Sum ofTotal Amount Metal Particulate Metal Particulate Metal Particulate TotalMetal of Particulate Treatment Amount Metal Amount Metal Amount MetalAmounts Metal Liquid mass ppt mass ppt mass ppt mass ppt mass ppt massppt mass ppt mass ppt Example C3 IPA 43 5.8 21 3.9 3 0.5 67 10.2 101Example C4 IPA 11 1.1 3 0.2 1 0.1 15 1.4 102 Example C5 IPA 12 1.3 2 0.10.2 0.02 14.2 1.42 103 Example C6 IPA 238 38 89 14 38 5 365 57 104Example C7 IPA 7 0.7 1 0.1 0.2 0.01 8.2 0.81 105 Example C8 IPA 9 0.5 20.2 0.2 0.01 11.2 0.71 106 Example C9 IPA 85 9.8 43 5.3 9 1.2 137 16.3107 Example C10 IPA 316 56 187 38 38 4.2 541 98.2 108 Example C11 IPA 385.3 29 4.2 9 0.7 76 10.2 109 Example C12 IPA 21 3.1 13 2.1 3.0 0.09 375.29 110 Example C13 IPA 5 0 1 0 0.2 0.01 6 0.38 111 Example C14 IPA 70.6 2 0.1 0.2 0.01 9.2 0.71 112 Example C15 IPA 43 5.6 38 4.3 5 1.1 8611 113 Example C16 IPA 216 41 89 17.6 38 5.6 343 64.2 114 Example C17IPA 358 63 101 21 29 4 488 88 115

What is claimed is:
 1. A storage container comprising: a storage portionthat stores a treatment liquid for manufacturing a semiconductor,wherein a mass ratio of Cr/Fe in a portion having a depth of 1 nm froman outermost surface of an inner wall of the storage portion that comesinto contact with the treatment liquid is 1 to 3, wherein the treatmentliquid includes one kind or two or more kinds of metal atoms selectedfrom the group consisting of Cu, Fe, and Zn, and a total content ofparticulate metal including at least one kind of the metal atoms is 0.01to 100 mass ppt with respect to a total mass of the treatment liquid,wherein a material of at least a portion of the inner wall of thestorage portion that comes into contact with the treatment liquidincludes perfluoroalkoxy alkane.
 2. The storage container according toclaim 1, wherein the treatment liquid is a developer or a rinsingliquid.
 3. The storage container according to claim 1, wherein thetreatment liquid has a pH of 10.0 to 15.0.
 4. The storage containeraccording to claim 1, wherein the treatment liquid includes asurfactant.
 5. The storage container according to claim 1, wherein thetreatment liquid includes a quaternary ammonium salt.
 6. The storagecontainer according to claim 1, wherein the treatment liquid includes atleast one selected from the group consisting of butyl acetate (nBA),N-methyl-2-pyrrolidone (NMP), isopropanol (IPA), ethanol, methylisobutyl carbinol (MIBC), propylene glycol monomethyl ether (PGME),cyclohexanone (CyHx), γ-butyrolactone (GBL), ethyl lactate (EL),dimethyl sulfoxide (DMSO), isoamyl acetate (iAA), a mixed solution ofpropylene glycol monomethyl ether acetate (PGMEA) and propylene glycolmonomethyl ether (PGME), methyl 2-hydroxyisobutyrate (HBM), methyl ethylketone (MEK), and propylene carbonate (PC).
 7. The storage containeraccording to claim 1, wherein the treatment liquid includes at least oneselected from the group consisting of butyl acetate (nBA), methylisobutyl carbinol (MIBC), and isoamyl acetate (iAA).
 8. The storagecontainer according to claim 1, wherein the treatment liquid includes atleast one selected from the group consisting of propylene glycolmonomethyl ether (PGME), cyclohexanone (CyHx), ethyl lactate (EL), amixed solution of propylene glycol monomethyl ether acetate (PGMEA) andpropylene glycol monomethyl ether (PGME), and methyl2-hydroxyisobutyrate (HBM).
 9. The storage container according to claim1, wherein the treatment liquid includes at least isopropanol (IPA). 10.The storage container according to claim 1, wherein the storage portioncomprises a void portion, wherein a void volume of the void portion inthe storage portion storing the treatment liquid is 50 to 0.01 vol %.11. The storage container according to claim 10, wherein the voidportion of the storage portion storing the treatment liquid is filledwith a gas in which a number of particles having a diameter of 0.5 μm ormore is 10 particles/L or less.
 12. The storage container according toclaim 10, wherein the void portion of the storage portion storing thetreatment liquid is filled with inert gas.
 13. A storage containercomprising: a storage portion that stores a treatment liquid formanufacturing a semiconductor, wherein a mass ratio of Cr/Fe in aportion having a depth of 1 nm from an outermost surface of an innerwall of the storage portion that comes into contact with the treatmentliquid is 1 to 3, wherein the treatment liquid includes one kind or twoor more kinds of metal atoms selected from the group consisting of Cu,Fe, and Zn, and a total content of particulate metal including at leastone kind of the metal atoms is 0.01 to 100 mass ppt with respect to atotal mass of the treatment liquid, wherein a material of at least aportion of the inner wall of the storage portion that comes into contactwith the treatment liquid includes at least one selected from the groupconsisting of polyethylene, polypropylene, polytetrafluoroethylene, andperfluoroalkoxy alkane.
 14. The storage container according to claim 13,wherein the mass ratio of Cr/Fe in the portion having the depth of 1 nmfrom the outermost surface of the inner wall of the storage portion thatcomes into contact with the treatment liquid is 2 to 3.